Click on the picture to enlarge the Schematic.

L6203 a H-bridge driver for dc motor control. It  can drive up to a 4A rating motor. There is very few external component, and it is easy to implement. For high current driving from 1A to 4A, it is advisable to mount a heat sink to prevent overheating to the IC L6203.

Speed control can be achieve by various duty cycle control signal. In robotic maneuver speed control is necessary to accelerate and de-accelerate the robot. If there is no speed control, the robot can easily skid or experience slow acceleration.

The schematic consist of 3 dc motor driver for Spotronic use. Two driver for left/right wheel’s motor, and the third one is for camera rotation motor.

Click on the picture to enlarge the Schematic.

DC motor control using relay is very simple compare to using transistor. It can drive very high current rating motor (depending on the relay current rating). However the relay is mechanical driven contact (produce sound), and can wear out over time.

There is not much control, only clockwise, anti-clockwise and stop.

Click on the picture to enlarge the Schematic.

This is a simple DC un-interrupt power system for DC powered device. When there is external power connected, the system will tap power from the external source and charged the internal battery at the same time.

When external power is withdraw, the relay will switch over which enables the internal battery to continue supplying power to the device.

The capacitor value is chosen, depends on the device. It function as a temporary supply source while the relay switches to another power source. This buffer ensure that there is no sudden dip to the power supply during the transition. If the device consume high power, a higher capacity capacitor should be use. Voltage rating of the capacitor as a guide, should be about 2 times the voltage of the supply.

The diode act as a block to prevent activation of the relay by the battery supply source. The current rating of the diode, as a guide should be about 2 times the connected device rating.

Click on the picture to enlarge the Schematic.

IC ADG451 is an analog switch. It can be used to switch signal on/off or can be configure to act as a signal multiplexer. There are other configuration of analog switch from this series (ADG451 ADG452 ADG453). ADG451 consist of 4 analog switches (active high), while ADG452 consist of 4 analog switches (active low) and ADG453 is a mixture of 2 active high/low.

This circuit is designed for switching Ethernet LAN signal.

Click on the picture to enlarge the Schematic.

Design Dated: 17 Oct 2006

This is a PWM circuit which generate duty cycle rectangle pulses using the IC 555 timer. The duty cycle is adustable by a potential meter (variable resistor) from 0%-100%. PWM signal can be used to switch on/off power transistor, which can then be use to control Motor speed, LED brightness, controlled power supply, and many more. Vcc power supply to the circuit is 7V for the LED. Power supply range is quite wide for IC 555. The IC can operate with voltage within 5V to 16V.

This circuit is designed to control the brightness of LED without the use of transistor to drive. For more information on using transistor to drive high current device, you can refer to project “Switch” at siongboon.com

Design Dated: 19 Aug 2012

This is a very basic circuit to interface to a piezo buzzer. The input is a PWM rectangular wave driving the sound/tone of the buzzer. Lower frequency result in a lower tone.

Click on the picture to enlarge the Schematic.

Design Dated: 19 Aug 2012

This circuit can control a DC motor forward/reverse. The PWM input control the speeed of the DC motor.

Click on the picture to enlarge the Schematic.

Design Dated: 20 Nov 2006

This is a serial data input to parallel output circuit. The circuits using 3 signal line, namely the data, data clock and latch clock to send the data to the IC 74HC595. Sometimes more output lines is required for control. With the constraint of limited ports from a microcontroller chip, this circuit comes handy in a project to extend the number of output ports up to infinity.

Each 74HC595 IC support 8 bit latched output, which can be cascaded to infinity number of 74HC595 IC, through is able to provide unlimited number of output ports. The trade-off for such a feature, comes with a delay time, and a relative longer firmware coding.

If the delay is not of an issue, this circuits can helps to extend the number of output ports, from 3 bit port output.

Attached is a function call routine to send the serial data to the circuit’s output. Written for the microcontroller PIC16F877a. ASM source code is here.

Click on the picture to enlarge the Schematic.

Design Dated: 20 Nov 2006

This is a parallel input to serial output circuit. The circuits using 3 signal line, namely the data, data clock and parallel latch enable to read in the parallel data from the IC 74HC166. This circuit comes handy in a project to extend the number of input ports for a microcontroller.

Each 74HC166 IC support 8 bit latching parallel input, which can be cascaded to infinity number of 74HC166 IC, through is able to provide unlimited number of input ports similar to the serial to parallel circuit shown above. The trade-off for such a feature, comes with a delay time, and a relative longer firmware coding.

If the delay is not of an issue, this circuits can provide the microcontroller with more inputs, from 3 bit port input.

Attached is a function call routine to read in data from the circuit’s port to the microcontroller. Written for the microcontroller PIC16F877a. ASM source code is here.

Click on the picture to enlarge the Schematic.

Click on the picture to enlarge the Schematic.

The schematic illustrate various method of interfacing line between a 3.3V and 5V digital circuits.

The information presented is from,

Download full article: 3V Tips ‘n Tricks, 41285A.pdf

Circuit design for interface (3.3V→5V)

Interface using commercial available level shifter IC (3.3V→5V)

Circuit design for interface (5V→3.3V)

)

1. Lamp Characteristic

LED is the latest lightings technology in town. I was excited about LED lights for the energy efficiency it can bring. Using less energy to light up the place. After exploring the technology, and conducting a series of experiments, I realised that LED is not as wonderful as I think it should be. The truth is, not all LED lighting lamp is efficient. It depends mainly on your application. Fluorescent lamp can have efficiency equal or better than LED lamp. For some applications LED will be better.

The following presents a list of energy saving lightings products that I have considered the best among the other alternative solution. The list consist of LED as well as fluorescent, because some fluorescent bulb solution can be as good or even better than LED bulb in terms of energy saving.

With a better understanding about the lighting technologies, it can help you make a better economical choice towards saving your electricity bill. The subsequent sections will present various energy saving products and some detail analysis. Alternative technologies will also be presented in a table format for easy comparison.

Most of the solutions that are presented are products from saveOne. The company has a strong focus in energy efficient products. Most of the efficient lightings or energy saving solution can be found there, be it LED or fluorescent. They also provide experiments and measurements to allow consumer to have a better understanding of various light bulb technologies. Some of the informations is made available for comparison with the help from their technical support. Besides lighting products, the company also sells other energy saving products. The main focus here is only on the lightings, so let us begin.

Dated : 2011-02-15

This was the very first set of LED bulb that I have tested. My boss actually wanted to showcase LED bulb in our smart home.

(Click image for larger view)
	There is this two model that caught my attention. One is 12W and 7W model.
	This 7W LED bulb measures to be about 6W
	This model measures about 8.9W
	This is a 12W CFL (compact fluorescent lamp) bulb and the consumption is 11W

The power consumption is a bit lower, but the Philips LED bulb price is quite high. The price that I have purchase at that time is about $40++. This is about 8-10 times price difference when compared to a CFL bulb (compact fluorescent lamp, or energy saving bulb).

These LED bulb do generate some heat. You can easily see it from the way the bulb is designed. Between the bulb and the screw, you can find the heavy chunk of metal. This is actually the heatsink which helps to dissipate the heat from the bulb. The lamp uses high power LED. These LED can generate very bright lights, but at the cost of the heat produce. Not all the electrical energy is converted to lights.

LED Ceiling Lamp

Product code: LEDCL2417

LED Ceiling Light (Surface, Round, 98*LED)
Wattage: 8W
Color: Daylight (6500k)

available from

saveOne Pte Ltd, Singapore, www.saveone.com.sg

My home toilet is bright using the LED ceiling lamps. (Installed on Jan 2012)

The LED ceiling lamps is make up many small LED bulbs. This 8W LED ceiling lamp provide brighter illumination at the center than the old CFL. The old 18W CFL (E27 base) that I used to have provides a brighter illumination on the ceiling than the LED lamp. There are pro & cons. LED is rather directional which is why the ceiling looks darker. However lightings to the floor area is very bright.

This LED ceiling lamps uses many little low power LED bulbs. The heat generated by these low power LED bulb is insignificant when compare to the fluorescent lamp. They do not generate heat, and no heat sink is required. The low heat lighting also means that the components and material can last longer when compare to heat generating lighting technology. In short, low power LED lightings is more efficiency compare to high power LED, fluorescent and other lighting technologies.

Measurement (for 8W LED ceiling lamp)

Wattage:6W
Current: 0.049A
Power Factor: 0.61

Measurement (my old 18W CFL bulb that was used to be in my toilet)

Wattage: 18.3W
Current: 0.118A
Power Factor: 0.664

There are other type of LED lamps that uses high power LED. These lamps uses only a few high power LED bulbs but can dissipate quite high heat. High power LED requires a heat sink (usually aluminium material) to be attached which helps to disspate heat.

LED Ceiling Lamp

Product code: LEDCL4015

LED Ceiling Light (Burger, Round, 208*LED)
Wattage: 15W
Color: Daylight (6400k)
Size: Dia 350mm

available from

saveOne Pte Ltd, Singapore, www.saveone.com.sg

2012-05-16 Upgrade My Kitchen Ceiling lamp.

I have been using the saveOne electronics ballast to power up my 2x kitchen’s ceiling fluorescent lamp for about 2 years. I wanted to change these fluorescent tube to LED but they are still functioning good. Finally one of the fluorescent (I think it is at least 5 years old) dies off. The very next moment, I ordered 2x LED ceiling lamps. Finally my kitchen is upgraded to LED.

The LED lamp itself is make of plastic, and the weight is very light. It is easy to install. I have managed to reuse the mounting holes from my old lamp by drilling holes on the plastic LED lamp base.

	The lamp that is nearer in the picture is the new LED burger lamp that I have installed. The further end is the old fluorescent lamp powered by the energy saving electronic ballast. I wanted to compare the two type of lamp side by side before I change both my ceiling lamp to LED. The LED version is very bright. Brighter than my old fluorescent lamp.
	Another photo taken. The exposure is less, and we can see both the lamps clearer. You can click on the photo for a larger view.
	Lamp view from bottom up.
	This is the 15W LED lamp with the cover removed. You can see that it consist of many little LED bulbs. They do not generate much heat even when operating for a long period of time. Your environment temperature can be a little cooler because of this lighting. Typical heat generated by a magnetic ballast can be very hot. You can try to touch your magnetic ballast after operating for 10 mintues at home. It will be very hot.
	The actual lamp with its plain cover.
	A close up view of how the inside looks like. There are a total of 208 small little LED bulbs.

Both my kitchen lamp used to be powered by magnetic ballast. The consume was about 40W for each lamp.

The changed to electronic ballast has reduced the energy consumption to about 25-27W.

The installation of LED lamp has reduce the consumption to only 15W. This is only 38% of my old 40W lamp. These LED does not generate much heat, through expected to last longer as well. Bright and efficient, I love it.

Next LED lighting to go will be my rooms.

available from

saveOne Pte Ltd, Singapore, www.saveone.com.sg

Other interesting LED ceiling lamps products.

These lamps are integrated with motion & LUX sensor. The lamps gets to operates in the dark. When the lamp sense motion, it will switch on it’s LED light automatically. When there is no activity for about a minute, it will switch off the light automatically. These features makes it suitable for your storage room, toilet and corridor.

Electronic PL lamp bulb G24 base (PLC)

Product code: CFLSI2154

Lamp base: G24
Wattage: 15W
Color: 6500k, Daylight

click here for product brochure

available from

saveOne Pte Ltd, Singapore, www.saveone.com.sg

Dated: 2012-01-15

It was quite difficult for me to accept the fact that in this technological era we are still using lighting technology that are so out dated. I was not so aware about our current lighting products and technology, until I had this chance to conduct experiment on saveOne’s product.

At first look, this product is no difference from the PL bulb that we normally use in our home or office building. I did not understand what is so special about this product, until I do my some market research.

The current PL bulb that we have in our home or offices actually uses the old magnetic ballast technology. It works exactly the same as a typical magnetic ballast with a normal fluorescent tube. You can read something about the old fluorescent technology here.

http://www.siongboon.com/projects/2010-08-22%20electronic%20ballast/index.html

The old fluorescent technology requires 3 components to work.

a starter , a magnetic ballast and a fluorescent tube to work.

This old technology has a number of disadvantage.

– Use more electricity energy.
– Need to wait for the starter to kick start the bulb.
– Generate more heat due to inefficiency (draw in more current).
– Operating at lower frequency.

The typical PL fluorescent bulb from Philips that you can find in the market does not requires external starter. Most consumer will find it a very convient product over the conventional fluorescent that requires a starter to operate. What most the consumers do not realise is that it is no difference from the old traditional inefficient fluorescent bulb.

So where is the starter? The reason that you don’t get to see any starter in the setup is because the starter has already been built into the bulb itself. A typical fluorescent tube has 4 pins. PL bulb has only 2 pin because the 2 other pin is used for a mini starter installed below the tube (near the socket). This also means that if either the tube or the starter component get damaged due to wear and tear, you will have to replace the whole PL bulb. The old setup allows you to change either the starter or tube if one of them is not working. PL bulb is easy to use but there is wastage. Not that eco-friendly. A working tube can ends up in your trush bin, just because the starter that was integrated into the PL bulb was not working.

You can easy tell if you have the old PL bulb install in your home/office. The lamp will flicker on and off for a few seconds before it can be fully turned on. The flickering is actually cause by the starter’s attempts to start up the lamp.

So what is so special about saveOne PL lamp?

Let’s do some technical measurement, to explain the differences.

This was a measurement that I took, comparing saveOne PL with a typical PL lamp + magnetic ballast.

Lamp	Photo	Wattage	Current	PF
10W saveOne PL bulb		9.1W	0.066A	0.63
typical 10W PL bulb + magnetic ballast		14.3W	0.158A	0.38

saveOne has designed the electronics to replace away with the magnetic ballast and starter system. The electronic control is more efficient consuming only 9.1W during the measurement. The PL lamp consume 9.5W at start up and drop down to 9.1W (steady state) after the tube gets to warm up. In contrast the typical PL bulb begins at 13.9W and rise up to 14.3W during the steady state.

saveOne PL lamp is driven by electronics. Users do not need to worry about the type of ballast to match with the lamp. The magnetic ballast PL bulb has a typical higher wattage consumption; this is especially true if the magnetic ballast is not match to the fluorescent tube wattage. In some cases, it wattage consume can even be higher. For the best efficiency in brightness, power consumption and lamp’s lifespan, the typical PL lamp has to match with the ballast of the correct wattage.

The current drawn by the magnetic ballast setup is also higher at 0.158A. Compare to the saveOne PL bulb 0.066A, it is about 2.4 times higher. The reason why a magnetic ballast draws more current is because of its inductive nature. Inductive load is actually an energy storage device and will draws/returns more current than its actual consumption. Unconsumed energy will be returned to the grid. This results in a higher current flowing through the magnetic ballast. The higher current flowing through a finite cable diameter will generate heat compare to a efficienct bulb that uses less current. These are actually energy losses. If you attempt to touch a magnetic ballast after switching your lights on for about 10 minutes, you will feel how hot it can be.

The power factor for the saveOne PL bulb is high at 0.63; the reason for the low current drawn. Power factor of 1.0 (which is the maximum possible reading) indicates that a device will draw the actual current it needs for its operation. Higher power factor means better efficiency.

The heat generated from the magnetic ballast is a waste of energy, and will tends to wear out the various component more. The heat will have indirect impact on the environment temperature and aircon electrcity wastage as well. If you feel the heat surrounding the old PL bulb, you can feel the heat. When you change old PL bulb, you might also find that the tube has the tendency to drop off from the base or the glass tube can break easily. These wear and tear can also expose the dangerous mecury content inside the florescent tube, which will contaminate your home/office environment.

saveOne PL lamp uses electronics to switch the fluorescent lamp. The higher operating frequency also plays a part in the efficiency of the lamp.

The saveOne PL bulb replacement over the old PL bulb is easy. There is no need to do any rewiring. Simply change the bulb. The electronics built into saveOne PL lamp is able to work with existing installed magnetic ballast. I was sceptic about its claim and also did a measurement on its performance when it is used with a magnetic ballast.

Measurement (for saveOne 10W PL bulb + magnetic ballast)
Wattage: 8W
Current: 0.042A
Power Factor: 0.74

The result was quite unexpected when I first do the measurement. The performance is even better without removing your existing magnetic ballast. This product is designed specially for consumer using the old magnetic ballast PL lamp, helping them to switch over to a more energy efficient saveOne PL lamp.

Even though the magnetic ballast was installed with the saveOne bulb, it does not generate much heat as compared to the old PL bulb. This is much expected with the low current that the bulb is drawing.

saveOne tube is designed in a spiral shape which allow more lights to be projected out. The fluorescent tube also contains triphosphor material which allows the tube to generate brighter light using less electricity energy.

This patented product from saveOne really earns my respect for the innovation that they have put in the area of energy saving. It changes my views about the old lighting technology that we are still using in Singapore. Many places are still using the olf PL bulb.

See the following comparison table for more information.

Comparison among various energy saving lightings for PL fluorescent lamp. (updated Jan 2012)

Description
Name	Electronics PLC Lamp	LED PL Lamp	Magnetic PL Lamp
Lastest Energy Saving Lamp	15W	12-18W	18W
Electricity Energy Cost Per Year see footnote.	$36.25	$29.00 – $43.50	$43.50
Electricity cost saving per month (when the old magnetic PL lamp is replaced)	$0.60/mth = ($43.50-$36.25)/12	$0 – $1.21/mth = ($43.50-$29.00)/12
Lamp Cost	about $8-12	about $30-50	about $4-6
Fast ROI (Return-On-Investment, when replaced with ballast + PL Lamp) Lamp Cost ÷ Electricity cost saving per month	about 13 months	about 25 months
Brightness	Triphosphor
Lower Heat Generated			magnetic ballast generate a lot of heat.
Easy to Install/Replace
Low Maintainance Cost
Instant On (no need starter)			`
Safety (robust mechanical design)	robust tube design	no mercury content	crack easily and loosen due to heat stress
Integrated Ballast (save space)			external ballast is required
High Power Factor			magnetic ballast has low power factor
Estimated Lifespan	7,000hr	30,000hr	7,000hr
Brand name in Singapore – Philips – PowerPac – saveOne

footnote:
(assuming 24 hour operation per day, base on Singapore’s Electricity Tariffs rate of $0.2759 cents as of Jan 2012)
Electricity Cost Per Year = Bulb Watt (W) x 24 Hour x 365 days ÷ 1000 x Electricity Tariff Rate ($/KWh)

Energy Saving T8 fluorescent tube

SuperTube

Product code: FLRSL1644

Lamp base : T8
Length: 4ft
Wattage: 16W
Color: Daylight (6500k)

click here for product brochure

available from

saveOne Pte Ltd, Singapore, www.saveone.com.sg

When I first got to know of this energy saving T8 fluorescent tube, it looks just like any ordinary T8 lightings. I have learned over a series of measurements and experiements that this is no ordinary T8 fluorescent tube. It has the performance comparable to a LED T8 tube, but at a cost much lower. The design also overcome some of the shortcoming of an ordinary fluorescent tube that are available in the current market. These have make it one of the most efficient and economical lighting tube among the rest (LED T8 and T5).

Taking a closer look, the product is actually a T5 fluorescent tube, covered with a protection covering. T5 is quite well known for its lighting efficient. The T5 tube is coated with triphosphor material helps the tube project out more light using less energy..

The product’s covering provides an extra protection over the fragile tube to reduce contamination due to the leakage of mercury vapor; a common substances that is contain inside all fluorescent tube. This protection is especially important in the kitchen area where food preparation work will be done. It is also desirable for low ceiling workplace where the tube can easily be damaged. Mercury is a health hazard substances, and it important that we handle fluorescent tube with care. The covering design reduce the chance of mercury containmination.

Actual measurement was conducted shows that the wattage of this product has the same wattage consumption to a typical LED tube. This energy saving performance comes from the electronic ballast that is integrated into the lamp product itself. With the integrated electronic ballast, the tube can be connected directly to your Live and Neutral electrical wire. This simplifies the electrical connection. It means that you can save more space. A normal T8 or T5 fluorescent tube which requires a starter and external electronic/magnetic ballast in order to work with, and this will take up precious space.

Normal T8 housing can be very bulky. Magnetic ballast, starter and starter holder are housed inside the enclosure.

Space saving T8 fluorescent tube socket for direct electrical connection. Useful for ceiling/wall cove lightings where space are very tight. Setup is cheaper as well without the enclosure, starter, starter holder and magnetic ballast.

The product’s built-in integrated ballast is also designed to work with your existing magnetic ballast. This means that you do not have to change any wiring or remove the magnetic ballast from your existing setup. Simply change the old T8 tube with this new energy saving tube, and remember to remove away the starter. The new lamp turns on its light instantly without the need for any starter.

You might wonder that with the magnetic ballast working together with this new product, will it affect the energy consumption? I had the same thought as well. Measurement were taken. By using the magnetic ballast together with the product, it has insignificant changes to its performance and energy consumption. In fact the power and current drop a bit. These can be explain by the measurement result which will be presented shortly.

The power factor of the ordinary T8 tube setup is poor. This is mainly due to the magnetic ballast which is an inductive component (which is only wire coil). The poor power factor results in higher current being drawn from the electrical grid. The current drawn is 4 times higher than the saveOne’s T8 energy saving product. With such a high current flowing through the magnetic ballast, it will generate heat. This is also why it feel burning hot when you try to touch the magnetic ballast which has been operating for more than 10 minutes. This is wasted energy as a form of heat. The heat also affect your environment temperature indirectly.

In contrast, this energy saving T8 lighting product uses much less current. Less heat will be generated. Even if this low current flows through your existing magnetic ballast, it will not generate much heat. The low current is transparent to your existing magnetic ballast; there are no loss.

	This is a ordinary T8 fluorescent lamp using a magnetic ballast. The temperature is 71.8°C is taken just behind the casing housing the magnetic ballast. It is so hot even on the outside. You can imagine how hot is the ballast inside.
	The whole lamp housing was removed from the ceiling and is placed on the floor. This ballast has been resting for about 10-20min. The temperature reading taken on the magnetic ballast surface is still hot at 61.0°C.
Click on the picture to enlarge.	A big contrast, another ceiling lamp housing was fitted with the saveOne T8 energy saving fluorescent tube. The magnetic ballast is still inside. Starter was removed and no wiring change was done. It has been turned on for the whole day. The temperature reading behind the lighting enclosure is only 35.0°C. This is only slightly more then the normal room temperature in Singapore. The heat is propably only from the fluorescent tube itself. The fluorescent tube itself when switched on, do produce some heat.
	As we can see, the drop in temperature is quite significant. The generated heat from the old T8 is simply a form of wasted energy.

The following measurement result shows that the power consumption for the saveOne T8 product is almost the same as a typical LED T8. Given the similar performance, the ROI (return of investment) of the product will be much better because the LED cost is high.

Lamp	Photo	Wattage	Current	PF
saveOne T8 fluorescent tube		16.1W	0.082A	0.953
LED T8 tube		16W	0.080A	0.952
ordinary T8 fluorescent tube		43W	0.429A	0.439

Note: wattage various around 36W- 45W depending on the magnetic ballast

The product has indeed impressed me for its efficiency when compared to a LED T8 tube. I have also done up a product comparison table to compare against other type of lightings solution to replace the old T8 magnetic ballast fluorescent lamp.

See the followings for more information on the comparison between more types of alternative replacement solution for T8 lightings.

Comparison among various energy saving lightings for T8 4FT fluorescent lamp replacement. (updated Jan 2012)

Description
Name	SuperTube	LED	T8 to T5 Adaptor	Electronic Ballast	Magnetic Ballast
Lastest Energy Saving Lamp	16 – 20W	16 – 20W	23 – 28W	28 – 40W	36 – 45W
Electricity Energy Cost Per Year see footnote.	$38.67	$38.67	$55.59	$67.67	$87.01
Electricity cost saving per month (when the old T8 tube is replaced)	$4.03/mth = ($87.01-$38.67)/12mth	$4.03/mth = ($87.01-$38.67)/12mth	$2.62/mth = ($87.01-$55.59)/12mth	$1.61/mth = ($87.01-$67.67)/12mth	—
Lamp Cost	about $18-$25	about $60-$90	about $12-$18	about $8-$12	about $5-$9
Fast ROI (Return-On-Investment, when replaced with ballast + PL Lamp) Lamp Cost ÷ Electricity cost saving per month	about 4-6 months	about 15-22 months	about 5-7 months	about 5-7 months
Brightness	Triphosphor		Triphosphor
Lower Heat Generated
Easy to Install/Replace
Low Maintainance Cost
Instant On (no need starter)
Safety (robust mechanical design)	protection against mercury leakage	no mercury content
Integrated Ballast (save space)
High Power Factor
Estimated Lifespan	7,000hr	30,000hr	7,000hr	7,000hr	7,000hr
Brand name in Singapore – Philips – AZ e-lite – Megaman – PowerPac – saveOne				28-32W electronic

footnote:
(assuming 24 hour operation per day, base on Singapore’s Electricity Tariffs rate of $0.2759 cents as of Jan 2012)
Electricity Cost Per Year = Bulb Watt (W) x 24 Hour x 365 days ÷ 1000 x Electricity Tariff Rate ($/KWh)

Comment:

As based on the comparison among various lamps technology, the latest energy saving LED and SuperTube lamp are both very energy efficient lamp.

LED is known to last longer than the fluorescent technology but the cost of the lamp is much higher. That is why the ROI (return on investment) is poor when compare to the fluorescent technologies.

The fluorescent technologies have similar ROI although the cost price is different. This is because the new fluorescent design has achieved an efficiency close to the LED technology..

SuperTube design has a cost slightly higher, but it offer more electricity saving, with a better protection against mercury contamination than the other fluorescent technology.

In terms of cost and efficiency, the SuperTube lamp offers a better choice over the lamps. If you are interested to find out about saveOne’s SuperTube lamps, you can contact them or visit their office for a demonstration or an experiment experience.

LED candle and chandelier bulb (compare to incandescent bulb)

Lamp base: E12, E14
Wattage: 0.3W (candle bulb 6xLED) , 0.6W (candle bulb 12xLED), 3W (chandelier)
Color: Red, White, Warm, Green

available from

saveOne Pte Ltd, Singapore, www.saveone.com.sg

I love these LED candle bulb. These E12 bulbs are usually used for the praying lamp on our Taoist altar table. It simulate the olden days of using candle flame..

	Candle bulb with its holder.
	A simple altar table using candle bulb.

Compare to the normal incandescent bulb 16W, these LED bulb only uses 0.3W. That is about 50 times saving in energy. The incandescent bulb can be very hot after turning on for a few seconds, and these can be quite dangerous especially with naughty children running around the house. These LED bulb remains cool after operating for the whole day. The lifespan of these LED bulb is much much longer compare to the incandecent version.

LED candle bulb (0.3W, E12), cool and longer lifespan	Old type, incandescent bulb (16W, E12), very hot and short lifespan. Cheaper.

The old incandescent bulb cost less than a dollar, a lot cheaper then the LED bulb which cost about S$5 to S$8. Considering the 16W energy that the incandecent bulb will consume, it will actually cost more to maintain it. This is even more significant if you operate the lamp for 24 hours per day. The electricity bill that you save within 2 months of operation can easily help you recover the cost of the LED bulb purchased. Per bulb would have save you about S$3 to 4 base on the electricity tariff rate of S$0.30/Kwh. Lifespan of incandescent bulb can be short, as the heat and frequent switching on/off can burn off the filaments inside.

For these LED bulbs the brightness is lower and will not be suitable if you have a lamp covering. The cover will reduce the brightness. Considering the energy saving, temperature, safety and lifespan that this LED bulb brings, it is a much more economical choice over a incandescent bulb.

Buy this LED Candle Bulb Now at the PIC-store

Another great bulb that I will like to introduce is the LED chandelier bulb which uses only 3W compare to the incandescent version which uses 40W.

A LED chandelier bulb (3W E14), hot but much better than the incandescent bulb.	The LED bulb when it is switched off.

The photo on the left is an old incandescent chandelier bulb (40W E14), very hot and short lifespan. You can see the thin filament inside the bulb.

This LED incandescent chandelier bulb uses a high power LED. The light is very bright and look very much like the incandescent bulb’s filament. The high power LED bulb do generate some heat but it is a lot less than the incandescent version. This LED bulb 3W uses about 13 times less energy than the conventioanl incandescent bulb of 40W.

These LED bulbs are worth recommending for their higher effciency, lower heat generated, safer and longer life span over the conventional incandescent bulbs.

Buy this LED Chandelier Bulb Now at the PIC-store

LED lighting strips

Lamp base: Bare wire strip
Wattage: 4.8W, 9.6W, 14.4W, 28.8W per meter
Color: White, Warm, Green, Red, Blue, Orange, Yellow, Purple, Cyan, Pink, RGB multi-color
LED bulb: 5050, 3528
Package: IP67, IP65, IP44

1meter/reel, 50mm cuttable section

30/60/120 LED per meter

Last updated: 2012-03-13

LED strip is getting more and more popular nowsaday. Unlike other lighting, the led strip is very flexible allowing it to bend over corner and curve. They usually comes in a roll of 5m per reel and can be easily extended or cut to length in a section of 50mm.

There is usually a black line to indicate the cutting point. The line is usually between the copper pad. You can actually cut anywhere along the strip. If the strip is not cut on the indicating line, you will end up losing about 3 LED at the strip end not lightting up. This is because the strip is usually design to have 3 LED connected in a series circuit.

The installation and wiring is very simple. It using a low voltage of 12V which is very safe to handle. There are also strip using 24V. You will not get electrical shock by touching the pair of 12V wire using your bare hand; neither will it cause nasty short circuit when it gets in contact with water. This make it suitable for installation near water or where it can easily get in contact with water or the user. Special area like toilet basin, aquarium tank lighting, floor area, bed side and lower section of the cabinet. It is much safer than any 230Vac lighting; about 20 to 30 times lower.

There are many style of installing the strip. You can lay the strips simply on the shelf. Some strips has sticker/adhesive tape on its back, allowing it to sticks itself to most surface. Remember to clean the surface before sticking the strips on it. There are also accessories which you can extend or secure the strips. The strips allows installation where traditional lamp installation is not possible.

	Non-silicon jacket strip comes with adhesive on the back of the strip.
	Mounting silicon bracket accessories to secure the LED strip.
Connector to extend the LED strip. Another type of connector design. Connector can be used for the wire as well.	The LED strip comes in a reel of 5m and comes with a wire dangling from both end of the strip. The strip can be cut into length. If a connection is required after the cut, there is also a connector available to join up the strip. The connection is simple and quick. No soldering of strip or wire will be required.
	LED strip’s socket to fit to the typical power supply adaptor’s DC barrel jack (OD=5.5mm, ID=2.1mm)

The strip is usually drive by a 12V switching regulator or power supply adpater. Like a battery, you should never short the positive and negative terminal of power adapter; the adaptor can be damage. A 12V power supply adaptor comes in various current rating. A longer strips requires more energy to light up, therefore a higher current rated power supply will be needed to drive it. A meter of 14.4W strips requires about 1.2A. If you are getting 3 meter, the current needed will be about 3.6A. The power adaptor that will be required has to be a minimum of 12V 4A. Usually I will give the power adapter more buffer. A rating of 12V 5A or more will be safer. If you use a lower current rated supply, for example 12V 2A, you will likely to cause internal damage to the power adaptor. Higher current rated power supply is better in performance, but is generally more expensive.

Power Supply Adapter or Switching Voltage Regulator
Form factor: Wall Plug usually available for low current rating	Form factor: Desktop usually available for high current rating

LED strip circuit is a relatively simple design. It is unlikely that you will damage the strip using a wrong rated power supply. Even if you connect the positive/negative priority in reverse, neither the strip nor the power supply will be damaged. The strip operates on 12V, and can tolerate minor voltage difference (10-13V). A voltage too high applied to the strip can damage the LED bulb.

There is a limit to how long the strip can be extended. 10m is the recommended maximum continous strip length. Extending it longer, you will find that the light intensity near the far end of the strip will become much dimmer than the other end that is near the power source. If your eye are sharp enough, you should notice the intensity difference within a 5m long strip itself. This flaw is due to the slim and narrow strip design (resistance), restricting the high current flow, preventing current to reach to the far end of the strip. The high resistance on the strip design also result in slight heat generated. This problem is more obvious with the high power strips.

You can improve the intensity at the far end of the strip by connecting the end back to the power supply. This will allows the current to reach the far end of the strip directly, without passing through the whole LED strips. To achieve a more consistant intensity, it is recommended to connect the strip in a shorter section of 2m each. Each 2m section should be connected directly to the power supply in a star wiring configuration.

The exact current consumption of the LED strips is slightly difficult to compute because of this flaw. Depending on the strip connection in series or parrallel the consumption can varies. The exact consumption can only be determine by a current meter. In general, the computation method as introduced eariler would be more than enough to drive the strip.

There are many type of strips, and they are usually classified by the following 4 characteristic.

The LED bulb or chip size 5050, 3528 is actually a number code for EIA standard footprint size. These standard footprint allows PCB designer to draw the correct pad size so the the LED can be mounted properly onto the PCB board. For some reason, these code has becomes a standard when ordering LED strips. 5050 actually also defines the LED size in two dimension 5.0 x 5.0mm. For 3528, LED size is 3.5 x 2.8mm. As a general guidance, 5050 LED has bigger chip size, and is expected to have a higher intensity (brighter) and wattage (consume energy) than the 3528 chip.

5050 led chip 5x5mm (Brighter and consume more energy)	3528 led chip 3.5×2.8mm

IP code (Ingress Protection Rating) is standard define a series of code to label product’s strength of resistance against dust and water.

IP20  no cover	IP44 covered with epoxy	IP65 covered with silicon jacket	IP68 covered with expoxy & silicon jacket
(offer no protection from water)	(dustproof, water resistance, splashing water cause no harm)	(dustproof, waterproof)	dustproof, watertight, immersion into water
	<- IP protection standard reference http://en.wikipedia.org/wiki/IP_Code

There are also LED strip that can change their color making use of RGB LED. There are also special LED strip that can generate lighting patterns. These strips will require a LED strip controller to work.

RGB LED strip looks no different from a single color strip. The noticable difference will be the 4 wire connector (black, green, red, blue).These lines will be connected to the RGB controller on the left, to allow color control of the whole strip.

This is another RGB LED. It is different from the RGB strip above. This strip can generate a pattern of colors on the strip. This means that multiple color can co-exist on the strip at the same time. The strip can be differential by the IC chip embedded onto the strip itself. Click on the photo to see the enlarged strip below. You will see the black rectangular block which is the controller IC. This strip will also need an external delicated color controller to drive its color. The external controller usually comes in a form factor of a box. – RGB pattern generating IC chip info

Below Kitchen cabinet

– Provide some light during the night time

Cove lighting

Toilet, and behind mirrors

LED strips operate at 12V, and is safer than T5 tube which operates at 230Vac. A normal T5 tube is made of glass and contain mecury content. Installing T5 behind the mirror which is reachable can be dangerous, comparing to the LED strip. The LED strip when submerge in water will not result in electrical short circuit. This will not be true for T5 tube.

Wardrobe

LED strips is slim and safe, allowing installation in tight space such as a closet or cabinet display.

reference:

http://jacksledprojects.blogspot.com/2011_10_01_archive.html

LED driver

Typical LED driver rating

Typical LED driver specification.

2. Various Lamps Technologies

This is meant to be a general reference for various lamp technology available on the market. The following information is not comprehensive for a detail one to one comparison.

Type of lightings technology	LED	Fluorescent	Induction	Halogen	Incandescent	Plasma	HID
Picture
Full Name	Light Emitting Diode						High-intensity discharge lamp
Typical Application	Room lighting	Room, High Bay, Hall lighting	Room lighting	Display cabinet	General lighting	High Bay, Hall, Street lights	High Bay, Hall, Street lights
Typical Wattage	10W	40W	40W	50W	40W
Electricity Energy Cost Per Day see footnote.	$0.0662	$0.2649	$0.2649	$0.3311	$0.2649
Electricity Energy Cost Per Year	$24.16	$96.65	$96.65	$120.82	$96.65

footnote:
(assuming 24 hour operation per day, base on Singapore’s Electricity Tariffs rate of $0.2759 cents as of Jan 2012)
Electricity Cost Per Year = Bulb Watt (W) x 24 Hour x 365 days ÷ 1000 x Electricity Tariff Rate ($/KWh)

3. Color Temperature

Defination used in Lightings

Color Temperature References:

http://www.feit.com/education/feitcolortemperature.html
http://micro.magnet.fsu.edu/optics/lightandcolor/colortemp.html
http://www.3drender.com/glossary/colortemp.jpg
http://www.theprojectorpros.com/images/learn/color_temperature_1.jpg
http://www.ofweek.com/Upload/News/2009-10/7/kelvin-color-temperature-scale.jpg

4. Linear Fluorescent

reference:

– http://www.answers.com/topic/fluorescent-lamp

Bulb Shapes

• Circline
• T5 (0.625″ dia, 15.9mm)
• T6
• T8 (1″ dia, 25.4mm)
• T10
• T12 (1.5″ dia, 38.1mm)
• U-bend
  

Singapore commonly used bulb shape & base is highlighted in bold font.

Base Types

• Miniature Bi-Pin
• Single Pin
• Medium Bi-Pin
• Recessed DC

Singapore commonly used bulb shape & base is highlighted in bold font.

5. Compact Fluorescent

reference:

– http://www.biddy-light.com.tw/lamp/PL-LAMP.htm

Bulb Shapes

• Single Tube 2-Pin
• Single Tube 4-Pin
• Double Tube 2-Pin/4-Pin
• Triple Tube 4-Pin
• Flat Quad 4-Pin
• Double 15mm
• PLL 4-Pin
• BR38
• R20
• R30
• R40
• R40 Plug-In
• A
• G Globe
• PAR20
• PAR30
• PAR38
• B13
• GU24
• Spiral
• Spiral Plug-In
• T20

Singapore commonly used bulb shape & base is highlighted in bold font.

Base Types

• G23
• GX23
• GX23-2
• G24q-1
• G24q-2
• G24q-3
• G24d-2
• GX24q-3
• GX24q-4
• GX24q-5
• GX25d-3
• 2G11
• 2GX7
• Medium E26 E27
• E12

Singapore commonly used bulb shape & base is highlighted in bold font.

G24 lamp & socket

6. Halogen

Bulb Shapes

• AR111
• BR
• BT15
• J Type Tubular
• JC
• JD
• T10
• JDR
• JDR/S
• MB
• MR
• MR-DC
• MR-GU10
• PAR14
• PAR16
• PAR20
• PAR30
• PAR36
• PAR38
• PAR46 PAR56 PAR64

Singapore commonly used bulb shape & base is highlighted in bold font.

Base Types

• Screw Terminal
• DC Bayonet BA15d
• G53
• G6.35 or GY6.35
• G8
• G9
• G4
• GU5.3
• SC Miniature Bayonet BA9s
• GU10
• Intermediate E17
• Medium E26 E27
• Mini-Can E-11
• Mogul End Prong GX16d
• Recessced Single Contact R7s
• SC Bayonet BA15s

Singapore commonly used bulb shape & base is highlighted in bold font.

Filament Types

• CC-2V
• C-6
• C-7A
• C-8

Singapore commonly used bulb shape & base is highlighted in bold font.

7. Incandescent

Bulb Shapes

• A Arbitrary
• BR Bulge Neck Reflector
• B Cylinderical
• CA8-CA10 Candelabra Base
• B8-B10 Candelabra Base
• CA8-CA10 Edison Base
• ER Elliptical Reflector
• B8-B10 Edison Base
• F Flame
• CA5 Candelabra Base
• G Globe Candelabra
• G Globe Medium
• MB Mid-Break Reflector
• PAR36 Parabolic Reflector
• PAR Parabolic Reflector
• PS Pear Straight Neck
• R Reflector
• S Straight Side
• T Tubular

Singapore commonly used bulb shape & base is highlighted in bold font.

Base Types

• Screw Terminals
• Slip-On Terminals
• DC Bayonet BA15d
• Cadelabra E12
• E14
• Intermediate E17
• Medium E26 E27
• Medium Side Prong
• Medium Skirted E26/Skt
• Mogul E39
• Mogul End Prong

Singapore commonly used bulb shape & base is highlighted in bold font.

Filament Types

• C-2V
• C-3A
• C-5
• C-6
• C-7A
• C-8
• C-9
• C-9M
• C-13

Singapore commonly used bulb shape & base is highlighted in bold font.

8. HID lamps (High-intensity discharge)

Bulb Shapes

• A23
• BT37
• BT56
• ED17
• ED18
• ED23.5
• ED25
• ED37
• PAR20 PAR30L
• PAR38
• R40
• T6 T7 T8 Double Ended
• T6 T7 Single Ended
• T15 T16

Singapore commonly used bulb shape & base is highlighted in bold font.

Base Types

• BY22d SC Bayonet
• FC2
• G12 Medium Bi-Pin
• R7s Recessced Single Contact
• POMB Position Oriented Mogul Base
• EX39 Exclusionary Mogul Base
• E39
• E26 E27 Medium

Singapore commonly used bulb shape & base is highlighted in bold font.

9. Specialty

Bulb Shapes

• ALR
• C7/C9 LED
• G6
• G7
• MR11 LED
• MR13
• MR16 LED
• PAR16 LED
• PAR20
• PAR30
• PAR36
• PAR64
• PAR46 PAR56 PAR64
• RP11
• R12
• S8
• T1.75
• T2
• T2.5
• T3
• T3.25
• T3.25/T5
• T4 E11
• T4
• T4.25
• T5/T6
• T6
• T7

Singapore commonly used bulb shape & base is highlighted in bold font.

Base Types

• E11 Mini-Can
• E12
• E17
• E26 Medium
• G4
• G6.35
• G5.3/GX5.3
• G9.5/GZ9.5
• P28s Medium Prefocus
• R7s
• SC Bayonet BA15s
• DC Bayonet BA15d
• SC Midget Flanged
• SC Miniature Bayonet BA9s
• Screw Terminals
• Slip Terminals
• Slide #5
• Plastic Wedge
• Wedge

Singapore commonly used bulb shape & base is highlighted in bold font.

Filament Types

• C-2F
• C-2R
• C-2V CC-2V
• C-6 CC-6
• CC-7A
• C-8 CC-8

Singapore commonly used bulb shape & base is highlighted in bold font.

10. Others

Bulb Shapes

• A-15
• A-19
• A-21
• A-23
• B-10 1/2
• B-13
• BA-9
• BA-9 1/2
• C-7
• F-10
• F-15
• F-20
• G-16 1/2
• G-25
• G-40
• P-25
• PS-35
• BR-25
• BR-30
• BR-40
• R-20
• R-30
• R-40
• RP-11
• S-8
• S-11
• S-14
• PAR-16
• PAR-20
• PAR-30S
• PAR-30L
• PAR-36
• PAR-38
• PAR-64
• PAR-84
• T-4 1/2
• T-5
• T-6
• T-8
• T-10

Singapore commonly used bulb shape & base is highlighted in bold font.

Base Sizes

• Mini Cand Screw E11
• Cand Screw E12
• Intermediate E17
• 3 Contact Med E26
• Med Screw E26
• Mog Screw E39
• 3 Contact Mogul E39D
• Mog Pf P40s
• Med Skirt E26/50×39
• Can DC Bay
• Can SC Bay B15
• 2-Lug Sleeve B22d
• 3-Lug Sleeve B22-3
• Med Pf P28s
• Mogul BiPost G38
• Screw Terminal
• Disc Base
• Single Contact
• Med BiPost
• Med Side Prong
• Ext. Mog End Pr.
• Mog End Prong

Singapore commonly used bulb shape & base is highlighted in bold font.

BA15s

BAU15s

BA15d

BAY15d

BAZ15d

BAZ15d-3

SBC B15d

BC B22d

Singapore commonly used bulb shape & base is highlighted in bold font.

MES E10

SES E14

ES E27

GES E40

Singapore commonly used bulb shape & base is highlighted in bold font.

G4

GY6_35

Useful accessories for lamp installation

1) ETON Connectors

http://www.wellho.net/regex/javare.html

Java Regular Expressions   java.util.regex

My first encounter with regex happens when I was using String.split() function. The split char is represented by special char used by regex. I thought the function is easy to use but is spending a lot of time figuring why the string cannot be split. I was splitting the IP address which is separated by the '.' dot or period. My colleague drop me some notes from the website, and now I finally know what really happen. Great article I must say.

Class typically use for wild card search in String.

The following are some char keyword in used by the regular expressions class. In order to use the char, use \ followed by the char or insert the printable string between \Q and \E

metacharacters->   ([{\^-$|]})?*+.

There are more about regex than I thought after searching the web.

http://en.wikipedia.org/wiki/Regular_expression

regex example

String str = "This is a sentence. This is a question, right? Yes! It is.";
String delims = "[ .,?!]+";
String[] tokens = str.split(delims);

String str[] = result.split("HWaddr | \\. |inet addr:| \\. |Bcast:| \\. |Mask:| \\. |UP", 6);
This splits the following chunck of text into

eth0 Link encap:Ethernet HWaddr b8:27:eb:87:9e:02
 inet addr:192.168.1.97 Bcast:192.168.1.255 Mask:255.255.255.0
 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
 RX packets:4670 errors:0 dropped:0 overruns:0 frame:0
 TX packets:2034 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1000
 RX bytes:526428 (514.0 KiB) TX bytes:257010 (250.9 KiB)

str[0] -> eth0 Link encap:Ethernet
str[1] -> b8:27:eb:87:9e:02
str[2] -> 192.168.1.97
str[3] -> 192.168.1.255
str[4] -> 255.255.255.0
str[5] -> BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
 RX packets:4599 errors:0 dropped:0 overruns:0 frame:0
 TX packets:1960 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1000
 RX bytes:522426 (510.1 KiB) TX bytes:249420 (243.5 KiB)
      

package sg.com.siongboon.mypackage; //Basic java class structure. Using a domain name as your package, ensures that it will likely to be a unique namespace.

public class ClassName
{
  private int myResult;

  static
  {
    //Similar to constructor which will be executed
    //before the object is created.
    //It can be use like a constructor for your static class object,
    //where a constructor is not allowed.
    //static initializer block, it is seldom used (see example on *.dll)
  } 

  public ClassName()
  { //class constructor
  }  

  public methodOne()
  { 
  }

  final public methodOne()
  { //method cannot be overriden by other class extending it
  }

  static public methodOne()
  { //method is the only instance. It will be common to all the class object
  }

  protected void finalize()
  { //method gets called when it is about to be delete by the garbage collector.
    //Should not be use as it is imposible to know when the object will get deletes.
  }

  public static void main(String args[])
  { //entry point for running this program
  }
}

//A simple illustration of Java access modifier, Private, Default, Protected, Public

Java access modifier:

public- Variables/methods using public modifier can be access easily by all objects.

protected- Protected members can be accessed by another package through inheritence. Class CC managed to access protected member C through inheritence. Class CC inherited Class AA, therefore member C becomes part of Class CC.

default- If there is no modifier specified, Java will treat it as the default modifier. Default members B gets a bit more difficult to access. Only classes within the same package can access to it. Member B using the default modifier can be access by Class BB. Class BB can creates an instance of Class AA or through static variable access to access to member B.

private- is the most restrictive modifier. The private member A can only be access within the class AA itselfs. Class AA being the creator, is able to access all it’s members A, B, C and D. It is recommended to start the data/method encapsulation using private modifier. Change the modifier when neccessary. There must be a good reason why private modifier is not use.

Future research the meaning on these defination:

What do these defination really means?

//defining a common interface for objects
public interface LiftButton
{
  //define all the methods/interface in the class
  public void openLiftDoor();
  public void closeLiftDoor();
  public void pressLiftFloor(int floorLevel);
  public void alarm();
}

Very often in our physical world, we share a common interface with many different type or brand of system.

Example is our elevator lift. The interface buttons are the same/similar in each brand of lift. The user need not require training in order to use the lift, because the operating procedure is the same as what the user has used before.

The same goes for our computer system. Each computer may be run by various brand/model of CPU/hardware/OS, but the keyboard/mouse interface remains the same.

Defining an interface helps us to define a common standard, such that when it comes a day where we need to swap an object (change CPU model), we can easily change it with minimal or without any effect on the system.

It is mentioned by Jim Waldo, in his book “Java The Good Parts”, that passing parameters through the method is evetually going to be of some sort of interface. You can pass parameters using object, but later down the road, there is a high chance that it will be later change to an interface as the coding grows comre sophisticated.

//Java do not have unsigned data type
//Representation of the unsigned for a signed data type.
byte temp;
int result;
result=(int)(temp[0]&0xFF);   //extract the unsigned value

long longNum = 289637082704667748;   //The literal 289637082704667748 of type int is out of range

long longNum = 289637082704667748L; //if the literal value is too big, L is required at the back

int result=(int)((1.26)+0.5);         //rounding off to the nearest integer




//'f' indicates that 1.5 is of data type float rather than a double.
//(any literal is intepreted as a double and not a float)
float x = 1.5f ;  
double x = 1.5;

//'l' indicates that 10000000000 is of data type long rather than a int .
//(any literal is intepreted as a int and not a long )
int x = 15 ;  
long x = 10000000000l;



//declare & allocate memory for byte & char array
byte remoteIP[] = new byte[4];
byte[] dataByte = new byte[]{(byte) 0xDB, (byte) 0xA1};
char[] dataBuf = new char[100];//declare & allocate memory for byte

//converting a byte array for string use
String dataStr = new String(dataByte,"ISO-8859-1");
//converting back to byte array after String manipulation
byte[] dataByte = dataStr.getBytes("ISO-8859-1"));

//Earlier method. (ineffective)
//Please note that byte data maybe lost after converting to string using this method.  
//The conversion uses a default charsetName; 
//if charset is not able to map the data to a char, it could convert it to the data 0x3F.
//In some case, a char 0xC2 may be inserted before a char which is > 0x7F.
String dataStr = new String(dataByte);
String dataStr = new String(dataByte,"US-ASCII");

//converting a string to byte[]
byte[] dataByte = dataStr.getBytes();
//converting a byte to char for string use (convert a byte to char)
char dataChar = (char) 0xDB;
//converting a byte to string for string use (convert a byte to String)
String str = String.valueOf((char)ch);
//more methods for dealing with bytes 
ByteBuffer byteBuffer = ByteBuffer.allocate(10);
byteBuffer.put(0x01);

for information about charset encoding.

http://www.anyang-window.com.cn/tag/java-encoding/page/3/

s = s.replaceAll("\\s","");      //remove invisible \r \n char
s = s.trim();                    //remove white space

//formatting a string like printf or sprintf
String str = String.format("Number=%2d, %f", 5, 1.56); //result>"Number= 5, 1.56"
String str = String.format("Leading Zero=%04d", 5); //result>"Leading Zero=0005"
String str = String.format("Hex value=0x%04x", 79 ); //result>"Hex value=0x004F"


DecimalFormat formatV = new DecimalFormat("###0.00");    //floating value to 2 decimal place
String str = String.format("%6s",formatV.format(value)); //right align
//value =  0.91, result -> "  0.91"
//value = 21.91, result -> " 21.91"
//value = 12   , result -> " 12.00"

//rounding off float double value to 2 decimal place
float unround = (float) 0.34456;
double roundOff = Math.round(unround*100)/100D;    //rounding off to 2 decimal place
logger.info((float)roundOff);                      //result = 0.34
    
float unround = (float) 0.34556;
double roundOff = Math.round(unround*100)/100D;    //rounding off to 2 decimal place
logger.info((float)roundOff);               


//convert a float or double to a more precision BigDecimal
BigDecimal precision = new BigDecimal(0.34556);    //try not to use a double or float converting to a BigDecimal. It will result in additional trailing numbers because floating number is never exact. Use String instead to be accurate.
BigDecimal precision2 = new BigDecimal("0.34556");

precision = precision.setScale(2, BigDecimal.ROUND_HALF_UP);  //setup BigDecimal to 2 decimal place, and round up.

precision = precision.setScale(2, BigDecimal.ROUND_HALF_EVEN);//Banker's Rounding (rounding to the even if number is in the middle 0.5 or 0.05, etc...)
//example: 0.1265 (3 decimal place) should be round to 0.126
//example: 0.12651 (3 decimal place) should be round to 0.127
//example: 0.1275 (3 decimal place) should be round to 0.128
//example: 0.1285 (3 decimal place) should be round to 0.128

Right align a 2 decimal place floating number.

If encounter floating point error while using a variable of float data type, try changing to the data type double or use int data type instead. If precision is absolutely necessary, use the object BigDecimal.

private enum BonjourService
{    
  //use enum if there is a fix defined number of constant
  //enum can help to restrict the number input choice for
  //the programmer to feed it into the method
        CAMERA, HTTP, PRINTER, IPP, PDL_DATASTREAM
}

private String getServiceProtocolName(BonjourService service)
{
  String servStr;
        if(service==BonjourService.CAMERA)
            servStr = "_camera._tcp";
        else if(service==BonjourService.HTTP)
            servStr = "_http._tcp";
        else if(service==BonjourService.PRINTER)
            servStr = "_printer._tcp";
        else if(service==BonjourService.IPP)
            servStr = "_ipp._tcp";
        else if(service==BonjourService.PDL_DATASTREAM)
            servStr = "_pdl-datastream";       
}

String str = "(" + BonjourService.CAMERA + ")";
String str = "(" + BonjourService.CAMERA.toString() + ")";
//str="(CAMERA)", enum variables can also be used as String object.


public enum BonjourService
{
  CAMERA("camera"),
  HTTP("http"),
  PRINTER("printer");

  //constructor cannot be public
  //constructor allows multiple parameters, so that
  //the enum can represent more than 1 parameter.
  private final String name;

  private BonjourService(String name)
  {
    this.name = name;
  }

  public String toString()
  {
    return name;
  }
}

Toolkit.getDefaultToolkit().beep(); //error beep tone (sound, bell)

Singleton structure will ensure that the class object can only be created once. Constructor has to be defined as private while the class variable & getInstance method is static so that they can be access with the object being created.

This is the first question that I ask myself when designing a new class object even since I learned about it; whether it can be created with multiple instance or only a single static instance of the object. In some application, especially when working with hardware devices, single instance is the only proper way to built your class. It can helps you to prevent mis-written codes, resulting in less bugs/crush program when the class is used by another programmer.

Instant timestamp = Instant.now();	//newer form of Timestamp method. (Java 8)
LocalDateTime timestamp2;               //
LocalDate date;	                        //immutable object. Cannot be changed once it is created (Java 8)
LocalTime time;	                        //immutable object. Cannot be changed once it is created (Java 8)

LocalDate date = LocalDate.now();
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy MM dd");//formatter
String text = date.format(formatter);					//format date
LocalDate parsedDate = LocalDate.parse(text, formatter);		//parse date

//Timestamp string, output string "2010-03-08 14:59:30.252"
java.util.Date date= new java.util.Date();
logger.info(new Timestamp(date.getTime()));

//Calendar, Date, Time (data & formatting function)
Calendar cal;
cal = Calendar.getInstance();
int hourday = cal.get(Calendar.HOUR_OF_DAY);  //24 hour format
int hour = cal.get(Calendar.HOUR);            //12 hour format
int am_pm = cal.get(Calendar.AM_PM);          //
int minute = cal.get(Calendar.MINUTE);
int sec = cal.get(Calendar.SECOND);
int msec = cal.get(Calendar.MILLISECOND);

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MMM-dd (EEE)");
SimpleDateFormat sdf2 = new SimpleDateFormat("hh:mm:ss aaa");
String data = sdf.format(cal.getTime());               //Format string for date, time
String time = sdf2.format(cal.getTime());

DateFormat df = new SimpleDateFormat("yyyy-mm-dd");
Date dataObj = df.parse("2014-02-25");                 //Parse string for date, time


log4j
Example: FactoryLog for logging info, error, debug, etc messages.

Similar to System.out.println();

Save to project folder /lib /lib (factory logger).zip

Save to project folder /resource /resource (factory logger).zip

(Details of log file setup can be found in the file “log4j.properties”.

Includes a 2nd example to config Log4j for logging in Tomcat.)

Log4j references:
http://logging.apache.org/log4j/1.2/manual.html
http://juliusdavies.ca/logging.html
http://www.laliluna.de/articles/log4j-tutorial.html

//Using LogFactory for debugging & logging example.
//Remember to include the path to "lib" & "resources" in the classpath
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

protected static transient final Log logger = LogFactory.getLog(ClassName.class);

logger.error("");
if(logger.isDebugEnabled())
    logger.debug("Class name:<" + getClass().getSimpleName() + ">");
logger.info("Class name:<" + this.getClass().getName() + ">");  //print out the class name

//print out the method name
logger.info("Method name:<" + new Exception().getStackTrace()[0].getMethodName() + ">");
logger.info("Method name:<" + Thread.currentThread().getStackTrace()[1].getMethodName() + ">");

How to add *.jar library?Encountered the following errors?log4j:WARN No appenders could be found for logger (javax.swing.JApplet).
log4j:WARN Please initialize the log4j system properly.
Remember to add in the libraries in your project classpath. For Eclipse IDE the classpath is indicated in the .classpath in the project root directory.Alternative you can add the lib as follows in Eclipse:1) Right click on your project name (under “Package Explorer”) and click “Properties” 2) Select “Java Build Path”, and choose tab “Source”. Add the folders “lib” & “resource” under your project folder. 3) Choose tab “Libraries”. Click “Add JARS…” and add the “commons-logging-1.1.jar” & “log4j-1.2.14” library files. 4) Done.

//Two examples to print out error messages:
e.printStackTrace();
System.out.println("Got an IOException: " + e.getMessage());

logger.error("Got an IOException: ", e);

Example: File Write

Very often to specify a file path using a string, we need to use double slashes instead of only one in Java string.

C:\\Users\\Harald\\Folder1\\Version1\\Folder2.

This is because a slash ‘\’ is a escape char in a string. In order to indicate a ‘\’ intention, we need to put 2 slashes. This means that it will be quite odd to a typical computer user as we usually uses only one slash.

One method is to use back slash instead of forward slash. The file object classes will automatically treat ‘/’ back slash as the normal ‘\’ slash in Window OS.

Old was of specifiying the path,

processDirectory=”D:\\doc\\Expenses Invoice”

A solution of specifying the path,

processDirectory=”D:/doc/Expenses Invoice”

This solution, means that the user need not specify double slash, which can be quite confusing.

Writing an class object into a file, and reading the class obj back from the file. This acts as a means to permanently save the state or values store in the object that you have created.

There are also codes written to generate files, so that you can detect where your config files are stored in the user or project directory.

This class monitor new files added or removed from the directory. The class extends TimerTask which execute the run process every seconds.

Check out below (WatchService class) for newer methods of monitoring files and directory.

//Reading a data stream with non-blocking mode 
private OutputStream out = null;
private InputStream in = null;
out = new DataOutputStream(sp.getOutputStream());
in = new DataInputStream(sp.getInputStream());
byte byteRead = in.read(); // -1 if there is no data 


//reading the int data stream from a binary file
import java.io.*;
import java.util.*;

public class BinOutputFileApp
{
  public static void main(String arg[])
  {
    try
    {
      FileInputStream fis = new FileInputStream("binary.dat");
      DataInputStream in = new DataInputStream(new BufferedInputStream(fis));
      int a = in.readInt();
      int b = in.readInt();
      System.out.println(a); //print int "42"
      System.out.println(b); //print int "45"
    }
    catch (IOException e)
    {
      e.printStackTrace();
    }
  }

Project example: reading_int_datastream.zipExample of the data in the binary.dat file:0x00 0x00 0x00 0x2A 0x00 0x00 0x00 0x2DActual int content represented in the binary file above:42 45

Other very good reference:- http://www3.ntu.edu.sg/home/ehchua/programming/java/J5b_IO.html (very good NTU website on data stream by Chua Hock Chuan),

Java Input & Output Stream (by Chua Hock Chuan).pdf

Note: There is another better generic methods to read *.properties. Read more about “Apache Common configuration”. Commons Configuration provides a generic configuration interface which enables a Java application to read configuration data from a variety of sources. Commons Configuration provides typed access to single, and multi-valued configuration parameters.

Note:
Class loader resources are often read-only; i.e. held in read-only files / read-only directories.
ClassLoader cl = getClass().getClassLoader();
Unable to obtain classloader using a static class.

Use Java Preferences API instead for configurable preferences.

Properties prop = new Properties();

try
{
  //set the properties value
  prop.setProperty("database", "localhost");
  prop.setProperty("dbuser", "mkyong");
  prop.setProperty("dbpassword", "password");

  //save properties to project root folder
  prop.store(new FileOutputStream("resource/config.properties"), null);
}
catch (IOException ex)
{
  ex.printStackTrace();
} 

//Writing or printing to PDF file.


Using PDFBox.

Download library pdfbox-app-2.0.0.jar

//Example of using Java to read excel *.xls or calc *.ods file

import org.jopendocument.dom.spreadsheet.MutableCell;
import org.jopendocument.dom.spreadsheet.Sheet;
import org.jopendocument.dom.spreadsheet.SpreadSheet;

//Getting the 0th sheet for manipulation| pass sheet name as string
spreadSheet = SpreadSheet.createFromFile(file).getSheet(0);
          
//Get row count and column count
int nColCount = spreadSheet.getColumnCount();
int nRowCount = spreadSheet.getRowCount();

System.out.println("Rows :" + nRowCount);
System.out.println("Cols :" + nColCount);
//Iterating through each row of the selected sheet
MutableCell cell = null;
for(int nRowIndex = 0;nRowIndex < nRowCount;nRowIndex++)
{
    //Iterating through each column
    int nColIndex = 0;
    for(;nColIndex < nColCount;nColIndex++)
    {
      cell = spreadSheet.getCellAt(nColIndex, nRowIndex);
      System.out.print(cell.getValue() + " ");
    }
    System.out.println();
}

This example shows how you can use java to detect the processes running under the Windows Operating System. It can a mean to detect if another Windows application or service or task is currently running.

If can even list out all the currently running processes.

The string user.name is the string key required to retrieve the system variables string. The following list present the other possible system variable that you can retrieve from System.getProperty(keyString);

Add your own variables to the java environment system variables.

java YourProgram -D keyString=”mystring”.

example:
java myJavaProgram -D sg.myhomedir=”E:\myJaveProjects\”

//Threading example
public class myThreadClass extends Thread
{
  //flag to control process flow to be in syn with other critical function
  private static boolean fIsSynProcess=false;
  //object holding the reference to this thread
  private Thread thisThread = null;

  public myThreadClass()
  {
  }

  public void run()
  { //getting the thread process ID
    this.thisThread = Thread.currentThread();
    String threadName = getClass().getName() + ” : ” + this.thisThread.getName();
    logger.info(“…thread Started: ” + threadName);

    while((!isStopRequested()))
    {
        while((!isSynProcess())) 
        {
        }
    }
    logger.info(“…thread Stopped: ” + threadName);
  }

  private synchronized boolean isStopRequested()
  {
    if(thisThread==null)
      return(true);
    return(false);
  }
  
  public void requestStop()
  {
    Thread tempThread = thisThread;
    thisThread = null;
    //interrupt for used to exit from blocking function in the run() method's while loop
    if (tempThread != null)
      tempThread.interrupt();
  }

  private synchronized boolean isSynProcess()
  {
    return(fIsSynProcess);
  }

  private synchronized void holdThreadRun()    //prevent the run thread to terminate
  {
    fIsSynProcess=true;
  }

  private synchronized void releaseThreadRun()    //allow the run thread to terminate
  {
    fIsSynProcess=false;
  }
}

The thread example also illustrate the use of the keyword “synchronized“. The java run time will ensure that those methods which are labelled as synchronized will not be excuted in parallel. This is to prevent two or more processes to access the same variable/memory which will cause data corruption or process locked issue. A program base on threading algorithm is likely to face such problems that can be resolved by implementing “synchronized“.For more explaination on synchronized, please refer to the following,

http://download.oracle.com/javase/tutorial/essential/concurrency/syncmeth.html

//Another method of writing thread
Object obj = new Object();
new Thread(obj).start();
Object class must contain a method run();

//Object class must implements Runnable and that contains a method run();



this.setDaemon(true); explains: setting daemon to true, will ensure that this thread is spin off from the main’s method thread. When a program execute from main entry point, main itself is actually a thread. If daemon is set to true, the sub-thread spinoff will be under the main thread. When the main thread is terminated, all sub thread will be terminated, shutdownhook can also be activated. If daemon is set to false, the thread spin off as another separated thread by its own. When the main thread is terminated, the sub thread will still exists (with daemon set to false).

public class ThreadClassShutdownHook extends Thread
{
  protected static transient final Log logger = LogFactory.getLog(ThreadClassShutdownHook.class);

  private myThreadClass tc;
  
  public ThreadClassShutdownHook(myThreadClass tc)
  {
    this.tc = tc;
    logger.info(this.getClass().getName() + " created. ShutdownHook registered.");
    Runtime.getRuntime().addShutdownHook(this);
  }
  
  public void remove()
  {
    Runtime.getRuntime().removeShutdownHook(this);
  }
  
  public void run()
  {    if(tc != null)    {
      logger.info("ShutdownHook activated for " + this.getClass().getName()
      + ". Thread: " + Thread.currentThread().getName());
      tc.requestStop();    }
    else    {
      logger.info("ShutdownHook safely release for " + this.getClass().getName()
      + ". Thread: " + Thread.currentThread().getName());
    }

  }
}

public class Abc implements ShutdownHookClass
{
  protected static transient final Log logger = LogFactory.getLog(Abc.class);

  private myThreadClass tc;
  private Shutdownhook sdh;
  
  public Abc()
  {
    sdh.addShutdownHook(this);
  }

  @Override
  public void shutdownHookActivated()
  {
    close();
  }
  
  public void close()
  {
    if(sdh != null)
    {
      sdh.remove();
      sdh = null;
    }
  }
}

Implementing Shutdownhook using my utilities.jar file. Download the latest version from the section under “My Java Library“

//-----------------------------------------------------------------------------
//Using Desktop class to open file, so that the code will be OS platform independent
//The default application will launch automatically with the file.
//-----------------------------------------------------------------------------
String fileName = "resource/documentation/operating manual.pdf";
try
{
  Desktop.getDesktop().open(new File(fileName));
}
catch(IOException e)
{
  logger.info("Error opening file " + fileName + ". The default program to open this file may not been set. Please set the default program.");      
}

//opening a file on the project root directory
Desktop.getDesktop().open(new File("image.gif"));
//opening a file relative to the project directory
Desktop.getDesktop().open(new File("imageDir\\image.gif"));
Desktop.getDesktop().open(new File("imageDir/image.gif"));
//opening a file using absolute file name
Desktop.getDesktop().open(new File("d:\\myproject\\imageDir\\image.gif"));
//opening a pdf file
Desktop.getDesktop().open(new File("d:\\mypdf.pdf"));

//-----------------------------------------------------------------------------
//Non platform independent code. (for Window OS)
//-----------------------------------------------------------------------------
//Open gif image file
Process p1 = Runtime.getRuntime().exec("rundll32 SHELL32.DLL,ShellExec_RunDLL " + "d:\\myproject\\imageDir\\image.gif");
//Open pdf file
Process p2 = Runtime.getRuntime().exec("rundll32 url.dll,FileProtocolHandler d:\\mypdf.pdf");

//force close the opened file
p1.destroy();

//-----------------------------------------------------------------------------
//Opening a Openoffice calc template (*.ots) as a calc file (*.ods)
//Using Desktop.getDesktop().open() will open the *.ots template file instead of a *.ods calc file
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
//Using Desktop class to open directory/folder, so that the code will be OS platform independent
//-----------------------------------------------------------------------------
//opening a local directory/folder.
Desktop.getDesktop().open(new File("D:\\programs\\eclipse\\_workspace\\InvoiceDataExtractor"));
//opening a remote network drive using network name/path.
Desktop.getDesktop().open(new File("\\\\BOB-PC\\Bob share folder"));
//opening a remote network drive using IP address.
Desktop.getDesktop().open(new File("\\\\192.168.1.95\\Bob share folder"));


//-----------------------------------------------------------------------------
//Non platform independent code. (for Window OS)
//-----------------------------------------------------------------------------
//open "InvoiceDataExtractor" folder
Process p = new ProcessBuilder("explorer.exe", "D:\\programs\\eclipse\\_workspace\\InvoiceDataExtractor").start();
//open "_workspace" directory and select "InvoiceDataExtractor" folder
Process p = new ProcessBuilder("explorer.exe", "/select,D:\\programs\\eclipse\\_workspace\\InvoiceDataExtractor").start();



Reference:http://docstore.mik.ua/orelly/java-ent/dist/ch02_01.htm

//Opening TCP/IP server socket
ServerSocket s = null;
try
{
  try
  {
    thisThread = Thread.currentThread();
    String myName = thisThread.getName();
      s = new ServerSocket(getServerListeningPort());
      logger.info("HID RFID Server ...\"START\"...   , Thread: " + myName);
    while((isSynProcess()) || (!isStopRequested()))
    {
      try
      {
        HidRfidReader hid;
        Socket incoming = s.accept();
        hid = new HidRfidReader(incoming);
        hid.setDaemon(true); //set this as a user thread. If startService thread ended, these user thread will end as well.
        hid.start();
      }
      catch(UnAuthorisedDeviceException e)
      { //ip address is not reconigze/registered. Print debug message and return to main loop to accept incoming socket connection
        logger.warn("Warning!!! <Unauthorised Access Detected> " + e);
        //detects authorised device access
        //return to check for other incoming connection
      }
    }
  }
  catch(Exception e)
  {
    logger.error("Unhandled Error: " + e, e);
  }
  finally
  {
    s.close();
  }
}
catch(IOException e)
{
  e.printStackTrace();
}
logger.info("HID RFID Server   ...\"STOP\"...");

UDP is a connectionless communication protocol and does not handle the integrity of the data being send. This does not mean that it cannot be implemented for communication that requires 100% error free communication. It simply means that the lower level protocol will not help you ensure that all your data bytes are being send over, and that your application will need to handle those error checking if you need it.

There are various way to setup your UDP communicates. Two methods are breifly state for your awareness.

– socket define wihtin DatagramSocket

– socket define within DatagramPacket.

For UDP communication to and only to one IP addressed device, you should define your socket in the object DatagramSocket. For packet communication with multiple UDP devices or acting as a listener, you can define your socket within the DatagramPacket object; there will be no restriction to which devices you can communicate within the network. UDP protocol is very flexible to implement.

Compute Broadcast address from IP address and network MASK

Playing *.mp3 and *.wav audio/sound files

import java.io.File;
import javax.media.Format;
import javax.media.Manager;
import javax.media.MediaLocator;
import javax.media.Player;
import javax.media.PlugInManager;
import javax.media.format.AudioFormat;



    Format input1 = new AudioFormat(AudioFormat.MPEGLAYER3);
    Format input2 = new AudioFormat(AudioFormat.MPEG);
    Format output = new AudioFormat(AudioFormat.LINEAR);
    PlugInManager.addPlugIn("com.sun.media.codec.audio.mp3.JavaDecoder", new Format[] { input1, input2 }, new Format[] { output }, PlugInManager.CODEC);
    try
    {

      String file_location = "d:/mp3dog.mp3";
      System.out.print("start thread mp3 play: " + file_location + "\n");
      Player player = Manager.createPlayer(new MediaLocator(new File(file_location).toURI().toURL()));
      player.start();
      
      file_location = "d:/mp3siren.mp3";
      System.out.print("start thread mp3 play: " + file_location + "\n");
      Player player2 = Manager.createPlayer(new MediaLocator(new File(file_location).toURI().toURL()));
      player2.start();
      
      System.out.print("Two MP3 files playing together.\nNote that the media playing thread is still running.\n");
      
      //delay for 10sec before forcing thread to close
      try{Thread.sleep(10000);}catch(InterruptedException e){}
      
      System.out.print("Ending play thread.\n");
      player.close();
      player2.close();      
    }
    catch(Exception ex)
    {
      ex.printStackTrace();
    }

Download the following
– jmf.jar
– mp3plugin.jar
– mp3siren.mp3
– mp3dog.mp3

• Download http://java.sun.com/javase/technologies/desktop/media/jmf/2.1.1/download.html and extract the file jmf.jar (Java Media Framework, JMF). Put the jar file under your project/lib directory.
• JMF only support *.wav and *.aiff files. Download the MP3 plugin to play *.mp3 files. Download http://java.sun.com/javase/technologies/desktop/media/jmf/mp3/download.html, and extract the file “mp3plugin.jar”. Put the jar file under your project/lib directory.
• Make sure to add the jars to the compiler command or import the jar files to your project..
• add the codes (on the left) to your project to playback mp3 audio files.

Command Pattern: ExecutorService example: ExecutorService_Queue.java, ExecutorService_QueueJob.java Command Pattern: Observerexample1: Observer command pattern.pdfexample2: Observer pattern – Wikipedia, the free encyclopedia.pdfexample3: JavaWorld – October – How-to Java_ Observer and Observable.pdf