Touchless Lighting Wall Switch

Touch-less lighting wall switch. Switch On/Off your room lighting without touching the wall switch.

Suitable for installation at public area or high traffic user premises.

Reduce germs bacteria virus condemnation.
Minimise touch surface that can have direct contact with Covid virus.

Touchless Lighting Wall Switch
Video Demonstration

Build-in electronic IR sensor is sensitive to hand activation on the wall switch. Wave one time to turn on the lights and wave again to turn it off.

Simple and sensitive touchless hand wave wall switch sensor. Very simple to use.

Contact us at for further information.

Check out our series of touchless contactless electronic wall switches for your other application.

Trellis Automated Roof Panel System

Product by Sunshade Trellis System Pte. Ltd. (Singapore)
Visit website:


Automatic motorised Trellis system to shelter you from wet rain and hot sun shine, while you still get the fresh airy breeze. Louvered roof panel system installed with a rain sensor to automatically close the panel when it rains.

Installed Examples of Trellis Roof Shade System

Airy indoor open space using Trellis roof system.

The trellis roof can also be installed for indoor/outdoor balcony to create a spacious cool and relax area.

Feel the outdoor air breeze without too much hot and sunny sun shine. Nice natural lighting and cool open space.

Trellis open close roof shade system for outdoor swimming pool.

Trellis roof system provides shades for your outdoor pool during a sunny day as well as raining days.

When the weather is good, the trellis can be open up to allow for shine and breeze through the open area.

Enjoy your pool with comfort.

Trellis shade roof system for indoor corridor.

This is an indoor trellis roof canopy structure installation for a corridor inside the house.

Allows outside natural light and air breeze to enter into the house.

Makes the house cooler, brighter while using less energy.

The rain sensing mode will automatically close up the trellis to ensure that your indoor environment is keep dry and clean.

Operating Instruction

The trellis roof control is simple to operate. One button to open and another button to close the trellis.

The trellis system also comes with a rain sensor. When rain is detected, the trellis shelter can automatic close up itself so that your corridor stays dry.

An optional external buzzer can be install for auditory feedback to the user.

Opening Closing Trellis

A single push and release on the open button, the trellis will open to its preset half opening position. This preset position can be adjusted form the blue color POT on the circuit board. Another push and release will fully open the trellis.

A single push and release to the close button will fully close the trellis.

For controlling of the trellis opening to your preference, you can simply push and hold the button, to open/close the panel, and release the button when the panel reaches the position that you want.

Rain Detection

Rain detection mode can be activated to automatic control the trellis when it rains. The trellis will automatically be closed and do not allow to be open until the water gets dry out.

To open the trellis manually while the trellis is still wet, you have to switch off the rain detection mode first.

User can select this rain detection mode via a switch. The rain sensor mode indicator will get light when this mode is selected. When it is in OFF mode, the indicator will be turned off. This indicator will blink when rain is detected. If the rain mode is switched ON, the lighted indicator will starts to blink when rain is detected. Even if the rain mode is switched OFF, the indicator light will still blink when rain is detected, just that the blinking rate is slower.

System Connection Wiring

This section shows how

Wall switch to open/close the Trellis and to set for rain sensing.
Wiring Connection Diagram (for single bay Trellis installation)

Low cost rain sensor can be connected to this board to detect raining event. If the rain sensing mode is active, the trellis will automatically close itself to shelter away from the water. If you like the trellis to reacts faster to the rain, you can choose to install optical rain sensor instead. It is more precise in the rain sensing and can react faster to raining and rain stopping. You can order optical rain sensor from PIC-CONTROL.

Trellis Roof Controller Board

This is the main controller board for the trellis automated roofing system. It is the main board for driving the geared DC motor of the trellis system. Design to drive geared DC motor with a rating at about 1A (when it moves), and a stall current at about 8A to 10A.

The following is the description of the controller board.

Electronic controller circuit board for Trellis Roof Shade System.

(01) 230Vac mains incoming power input

230Vac is required for charging of the SLA battery.

(02) Indicator for 230Vac incoming power

Green indicator will gets lighted up when there is power coming from the 230Vac input.

(03) Fuse for 230Vac

Fuse of 1A is recommended for protection from the 230Vac incoming mains power source.

(04) Fuse for Battery

Fuse of 10A to 15A is recommended for protection from the battery.

(05) SLA Battery

Sealed Lead Acid Battery. Recommending 12V 1.3Ah capacity battery (97 x 43 x 51mm). Larger size 12V 7Ah SLA battery (152 x 66 x 94mm) can also be use.

This battery is used for driving the DC motor of the Trellis.

(06) Indicators for Trellis motor

When the controller is driving the Trellis motor to close, Green indicator will gets lighted up. For opening of the Trellis, Yellow indicator will gets lighted up.

(07) Motor Wire polarity (closing the Trellis)

Motor wire polarity for closing the Trellis panel is motor positive terminal on the left (pin 1), and negative terminal on the right (pin 2). Apply this polarity should activate the motor to close the Trellis.

(08) DC Motor output

DC motor output is design for driving a DC motor up to a maximum current of 10A. Typical operating current is about 1A, and can spike up to 8A to 10A when the motor is in a stalled position.

(09) Mounting Holes M3 x 4

Mounting holes available at the 4 corner of the board. Design for M3 screw mounting. Distances between the mounting holes are about 91.5mm apart.

(10) Onboard indicators

Indicators onboard for technician monitoring and troubleshooting use.

(11) Rain Sensor interface

This interface allows a simple resistivity rain sensor to be connected via two wire, signal and ground pins.

It can also connect to a more sensitive and responsive optical rain sensor for a better user experience.

(12) User switches and buzzer interface

Switch buttons for user to control and beep sounder feedback.

  • Open Trellis
  • Close Trellis
  • Rain Sensing Mode
  • Bay Select
  • Beep Sounder

(13) External Indicators

User indicators for operation and monitoring.

  • RUN
  • BAY 1 (available in 4 bay controller board)
  • BAY 2 (available in 4 bay controller board)
  • BAY 3 (available in 4 bay controller board)
  • BAY 4 (available in 4 bay controller board)

(14) Debugging port

USB debugging port for monitoring purpose. It is a virtual serial communication port with the following settings,

  • baud-rate 115200bps
  • No Parity
  • 8 Data bits
  • 1 Stop bits

(15) DIP switches

— Not available —

(16) Test switch

— Not available —

(17) Trellis position adjustment POT

When the open button is pressed for the first time from the Trellis panel closed position, the panel will open to the half open panel position. This half open panel position can be adjusted to your preference by adjusting this (17) Trellis position adjustment POT.

Battery Power and Protection System

The whole system is powered by a 12Vdc SLA Battery (Sealed Lead Acid Battery). A battery capacity of 1.3Ah is enough for typical operation.

The charging of this SLA battery is supplied via the 230Vac power input. This power do not supply power to the trellis. It is only used for charging the connected SLA battery. If the SLA battery is not connected, the system will not be able to operate correctly. This 230Vac do not have enough power to drive the trellis motor. A 1.3Ah SLA battery capacity can drive the Trellis for about 30min to 60min without any charging. It is ok to install a high capacity battery if want the system to operate longer when AC power is not available (A power blackout scenario).

A battery monitoring is designed onto the system. If the voltage level of the battery falls below a healthy level, the ERROR indicator will start blinking. When this happens, the controller will only allow user to close but not open the trellis. This is to protect the battery from over draining itself, and to conserve the energy so that it can have enough power to close up the trellis when it detect rain. If the blinking appears, you can simply wait for a while. The battery will be charged up, and allow for normal operation again. This can happen when someone is operating the trellis for a continuous period of 30min or more, or if the battery becomes faulty after long use.

It is recommended to replace the battery every 4-5 years of operation.

The system ERROR indicator will appeared to blink faster if the battery is suspected to be faulty. If this happens, leave the system alone for 24 hours. If the ERROR indicator blinking persist, please contact for technical support. It could likely be cause by the following…

  • No incoming 230Vac power supply.
  • Faulty charging circuit.
  • Battery is faulty (normal wear & tear).

The technician will diagnose and help you rectify the problem.

Technical Specification

  • Board power consumption is about 1W, up to 12W max
  • AC Power Input: 230Vac 0.1A (for battery charging purpose)
  • DC Power Input: Sealed Lead Acid Battery SLA 12Vdc 1.3Ahr (for motor operation)
  • Output driver support geared DC motor of 12Vdc 1A (10A max rating)
  • Support low cost resistive, or high precision optical rain sensor.

Cable current capacity for the Battery and Motor can operate peak at about 10A. Cable gauge size of AWG16 is recommended.

Trellis Controller Board Dimension

The physical board size is about 99 x 99 x 36mm.

Propose M3 mounting hole position is 91.5 x 91.5mm.
(mounting hole size is 3.2mm, suitable for M3 size screws)

Trellis Controller Board Dimension

The weight of this board is about 350g.

Deployed Site Installation

This is a installation for a single bay Trellis controller.

The board requires a 12Vdc Seal Lead Acid battery to function and for powering up the motor. Battery as small as 12Vdc 1.2Ahr battery can be use. (can continuously operates for about 45 minutes without the charging 230Vac power mains)

Trellis controller installation


Symptom ObservationPossible Cause
Error Buzz ToneThis is the most common feedback from a user. A low sound tone sounded when the switch is pressed. This can occurred when the Trellis is not allowed to be opened when it is raining and the rain sensing function is enabled.

Error buzz tone will also sound when you are trying to open the Trellis when the battery charge is low or the battery is faulty.
ERROR Indicator Blinking (slow).Battery voltage is low. Low in charge. This may also happen if 230Vac is not connected, or the charging circuit is faulty. If the system has been operating open/close action for long period of time, this may happen too. To conserve energy during this period, the Trellis can be close but cannot be open. You can wait for 24 hrs for the battery to be charged up before you can operate it normal again.
ERROR Indicator Blinking (fast).Battery voltage is super low. Battery probably needs a replacement.
Please call for technical support.
Cannot open Trellis.Check if ERROR indicator is not blinking. If it is blinking, read up the possible cause above. You can

If the Rain indicator is blinking.
The Trellis will not allow to be open, if battery level is low. You can wait for 24 hrs for the battery to be charged up, and attempt to open again.
The trellis will also not open if the rain sensing is enabled and water is detected. You can disable the rain sensing function, and open the Trellis.

If no indicator is blinking and the Trellis cannot be open, please call for technical support.
Cannot close Trellis.Please call for technical support.
Trellis do not automatically close when it rains.Please ensure that the rain sensing mode is enable.
If rain sensing mode is enabled and the Trellis do not close automatically when it rains, please call for technical support.

Board Voltage Measurement

With reference to the Gnd pin and with the battery disconnected, the voltage measured from the board labelled no. 1 to 4 should be as follows,

  1. Vcharge = 14.4V (battery charging voltage)
  2. Vbatt = 13.6V (battery voltage)
  3. Vcc = 13V (unregulated supply to the circuit)
  4. 5V = 5V (regulated supply to the circuit)

Contact Us for further details.

This system is designed and sold by Sunshade Trellis System Pte. Ltd.

Contact them at +65 6368 9800 (office phone), (email)

Click here to visit their website at

Also check out other automated awning retractable roof shade system.

Compare NB-IoT with LTE-M

reference from


(eMTC, Cat-M1)
QoS (Quality of Service)LowHigher
Cellular TechnologyYes (using existing cellular network)Yes (using existing cellular network)No
(non-cellular LPWAN)
For mobile applicationNo (for static only)Yes (cellular switching)No
Latency1.6 to 10 sec100 to 150ms
In-door applicationBetterGood
CommunicationHalf-duplex Half-duplex
Devices talk less oftenDevices talk less oftenDevices talk more often
Good if only a few devices is expected to be used in the remote area.same as NB-IoTGood if many devices are deployed in area the same area nearby.
CostVery Cheap
Brand New methodLight version of LTE.

Telecom Connectivity Offer

Some of the offer from Mobile Network Operators (MNOs).

International Sim Card for NB-IoT connectivity

Evidence suggesting that NB-IoT is a method of using existing Telecom cellular network for IoT devices

Company supplying NB-IoT module

Other lists of manufacturer brands for NB-IoT modules can be found here,

<- Back to Bluetooth Resources Page

CEPAS Card Key Holder [PIC-345]

Wall-mounted cardholder that reads CEPAS card for authenticating user’s identity for the usage of facilities. Using CAN number is a convenient registration of the temporary guest user.


  • Office room energy saving.
  • Meeting room usage.
  • Gym room booking.
  • Scheduled lecture hall lessons.
  • The authorised user of a facility.
  • Hotel card key energy-saving, and electricity control.
  • User guest registration.
  • Authorised operating of machines or system.


  • Read the CAN number of a CEPAS card (Ezlink or NetFlashPay)
  • Communication RS485 (other mode is available, RS232, Wiegand)
  • Optional board for network communication and power switching through the mechanical or solid state relay.
  • Operates from 12V


Face Plate size 86 x 86mm
Face Plate Dimension Drawing

Wall Mounting Method

This CEPAS card key holder is to be wall-mounted like a typical light switch in Singapore. It can be flush/surface mounted onto the standard 86 x 86mm wall box.

Wall Flush Mount Plastic Box (86 x 86mm)
Wall Flash Mount Metal Box (86 x 86mm)
Wall Surface Mount Box (86 x 86mm)

Go back to CEPAS card reader product page.

Sensors Data Logging

Data logging system design for sensors monitoring and test data recording. PIC-CONTROL can custom design a logging system specifically for your business use.

Sensor data logging system. Custom Design.

Sensor Data Logging Features

  • Type of Sensor Interface
  • Data Log Interface
  • Time-stamp of Data Logged
  • Power Supply

Type of Sensor Interface

There are many types of sensor connection interface.

  • Voltage ranges 0-3.3Vdc, 0-5Vdc, 0-10Vdc
  • Current interface 4mA to 20mA (Old standard, but still commonly used)
  • Digital communication interface, I2C, SPI, USART, RS232, RS485, Ethernet
  • Wheatstone Bridge

Data Log Interface

There are a number of data interfaces to choose from. It depends on your application.

Data collecting using a memory card is suitable for a standalone application where you want to leave the system to do the measurement or monitoring. You can collect the data at a later time, and open the file with your Microsoft Excel or OpenOffice Calc software for manual data analysis. The logged data can be presented with a timestamp for your archive. The amount of data collected will depend on the data being logged, the memory size of the storage and the time frequency of each data sample.

For an application that requires real-time data collection or real-time data analytic, you should consider using Ethernet communication line. Ethernet communication system is also more efficient when you are collecting from a number of sensors deployed to various different location.

  • microSD memory card
  • USB Thumb Drive
  • Harddisk
  • Cloud Server, Webserver data storage
  • Ethernet communication network
  • Wireless WiFi, Bluetooth, XBee
  • USB
  • RS232, RS485

Wireless sensors and equipment for monitoring weight. Sensors’ data are being transmitted via the internet for data logging to the cloud server.

XBee wireless sensors collecting data and sending them to the internet cloud.     Weight sensor monitoring through the internet WebService.

Timestamp of Data Logged

Date and time logging is typically necessary for analytic. This is also known as the data timestamp. This is especially useful for fast changing sensor data. Data logged can be archived for future reference.

Power Supply

The recommended method of powering up the data logging system is to use the wall mains 230Vac power supply.

For outdoor data collection, you may like to have your data logging system plugged to your vehicle for power or have it powered up from a battery.

A logger system can have the battery built in. There is a limit to how much power a battery can supply. For longer data collection usage, a large size battery will be needed. It usually means more bulky and heavy. There will be a charging function to charge up the built-in rechargeable battery.

Sensor Storage

Built case for storing sensitive equipment and dedicated sensors. Neat and protect against wear and tear.

Easy storage for your equipment and sensors

Custom Data Logging System

Email PIC-CONTROL today for your custom sensor data logging system. We are able to design and custom built the system for your business. Custom built set starts from S$2500 and above.

Rain Detection & Alert Notification System

Rain detection alert and notification system

Rain Detection (Alert Notification Process)

  1. The Rain Sensor that is installed outdoor detects raining.
  2. The indoor rain signage gets illuminated to indicate that it is currently raining outside.
  3. An alarm sounds to alert nearby personnel.
  4. Personnel can push the mute button to acknowledge the alert.
  5. The alarm can be muted, but the rain signage is still illuminated as long as it is still raining.
  6. Rain signage will be turned off when the raining activity is stopped for about 2 or 10 mins.
  7. The buzzer will not sound off again if the rain is stopped for less than 30 minutes.

Optional Features for Rain Detection System

Email Alert Notification

  • Email alert notification.

SMS Notification System

  • Option SMS alert using online cloud services.
    • Cheaper than traditional monthly SMS subscription sim card.
    • No need SMS modem or SMS sim card.
    • Requires SMS cloud service subscription.
    • Requires internet connection.

Wireless Connectivity

  • Wireless connectivity over 300-500m (in open space).

Rain Detection for Outdoor Premises or Activities

Rain sensor can be used to enhance the safety of outdoor activities. Outdoor play area can be deactivated when rain is detected to discourage children from their playing activities.

Rain detection for safe outdoor water play area activities.

Custom Rain Sensor Automated System

The rain sensor system can also be integrated directly with automated awning shade system, automated gate, door or window system.

It can also be used as a sensor to alert or halt outdoor aqua playground system to protect children from dangerous activities when the weather is bad.

Check out this page for more information about this wet weather rain sensor.

Contact PIC-CONTROL for further information on your automated rain sensor control system today.

Contact our sales for further information for a custom rain detection alert system.

Thermal Sensor

Thermal imaging sensor module

Thermal Sensor can detect the temperature of a subject without any physical contact. The technical name for the sensor is known as Thermopile Sensor. The sensor is able to detect the temperate of the surface of an area from a distance through the air. This is possible because the sensor is able to pick up the radiated heat in the form of IR (infra-red) from the subject.

Thermal Imaging Sensor is getting more and more popular compared to the vision camera. While the typical vision camera (CCD) picks up colour from the scene, a thermal camera picks up heat image. This helps the system to easily differential objects base on heat rather than colour. The thermal sensor is often used to detect dangerous hot surrounding and also to detect the presence of people. A technical name for Thermal Sensor is known as Thermal Array Sensor.

mini thermal sensor

Thermal Array Sensor is low in resolution compare to the vision colour camera. A high-resolution version (Thermal Imaging Camera) is still quite costly. Thermal array sensor (low resolution) is a more cost-effective sensor and is enough to serve its purpose.

Temperature sensor

Thermal Array Sensor Available in the Market

D6T-44L-06 (4×4 pixels), D6T-8L-06 (8×1 pixels)

datasheet: thermal-array-sensor-d6t.pdf

D6T-xxL-06 is available online from element14, Mousers Electronics or Digi-Key Electronics


TPA81 (8×1 pixels)

datasheet: thermal-array-sensor-tpa81.pdf

TPA81 is available online from sgbotic or Robot Store (HK)


Grid-EYE, Infra-red Array Sensor, AMG88xx (8×8 pixels)

datasheet: thermal-array-sensor-grid-eye.pdf



PIC-CONTROL customised the electronic solution for your businesses. For thermal sensing application and inquiry, you can contact our sales engineer or visit our website to learn about our other electronic engineering services.


Observatory Dome Automation Control System

Dome Automation Control for Astronomy

automated electronic controlled dome slit telescope

Astronomy Automated Control for
Observatory Dome


Customised integrated dome control system with the astronomy software “TheSkyX Pro” from SOFTWARE BISQUE and “Boltwood Cloud Sensor 2” from Diffraction Limited.

automated electronic controlled dome slit telescope

Paramount ME Mount II (Equatorial Mount) for the telescope, inside an Observatory Dome Motorised 3.0m Steel Astronomical Dome.

integration for dome control software

The Paramount ME Mount II is big and filled with many advanced features for astronomy observation.The multiple axis equatorial mount poses a problem when deployed in a small and tight observatory dome. The mounted telescope and its allowed movement are as big as the dome’s space available. The default dome azimuth generated from the SkyXPro software is not aligned with the telescope view.Software Re-mapping of Dome slit opening position to cater for any form of automated telescope system which the scope vision is offset from the centre of the small dome.

Dome Azimuth Mapping File to align the dome slit to the correct direction.

Screen capture of the dome’s azimuth mapping file. This mapping file ensures that the dome slit opening is always following the telescope mounted on the Paramount ME Mount II.

electronic dome automation system integration

Testing and commissioning the dome control system.

Java Program to Automate Observatory Dome Control

Java running at the back end controlling the hardware of the dome automation system.

automation electronic for the controlling the integrated dome slit

Junction box for Automated Dome Controller. The controller uses solid state controller (no mechanical wear and tear, no mechanical noise), long operating lifespan.

Weather Sensor for Observatory Dome Automation ControlWeather Sensor Status Report

Boltwood Cloud Sensor 2 weather and rain sensor to ensure that the telescope is protected from the bad weather.

SkyXPro Software Telescope Control Interface

SkyXPro Telescope and Dome control software interface.

Contact PIC-CONTROL today
for your Automation Control System Integration.

Feel free to contact us.

pic-control logo

Rain Sensor

Looking for a rain sensor product to help you detect rain water for your automated system?

Buy Your Rain Sensor Here

Rain Sensors

There are so many types of rain sensor technologies to choose from. It is important to understand the various rain sensors so that you know which one is the most suitable for your project.

Some rain sensors are cheap, while some are durable and robust against wear and tear. The even higher-end rain sensor can even detect the weather even before it starts raining down water. So which sensor should you go for?

Here, I will be showing you various type of technologies available for detecting rain and where you can buy the sensors.

Smart System

Singapore is a tropical country near the equator of the earth. We get a lot of sunshine as well as wet rainy day throughout the year. It can be sunny now, and the sky can turn dark the very next moment. Having a sense of the weather from the condition of the current sky can be difficult. Rain sensors can help alert us or automate our system when raining weather is detected.

rain detection alert system 

Rain does bring us cool air, comfortable and relax. It also brings in some inconveniences into our life. We travel out with our umbrella. Closing the window to keep the rain out. Worrying about the clothing that you are drying outside now. Looking across the raining street, watching your neighbour’s clothes soaking wet while you urgently retrieving your clothing into your house. Alerting neighbours who are not even aware of the rain. Rain is a daily affair that we have to be constantly paying attention to.

What we need is a smart system that can help us live with the inconvenience raining situation. A smart system that can detect the rain and alert us to bring in our drying clothes. A smart system that can remind us to close our windows.

We need a rain sensor that can automatically send out a notification to alert us. An automatic weather sensor that can alert the neighbourhood, the rain is coming. We need a smart office/home automation system to improve our lifestyle.

Type of Rain Sensors (Which one to choose?)

Selecting a suitable rain sensor for your automated rain detection system application is important. It is good to learn the range of rain sensors available on the market, and understand their advantages and disadvantages.

There are many methods of rain detection. You can read the following sections to understand more about the advantages and disadvantages of each of the rain detection method.

Our recommendation for outdoor rain detection would be the optical rain sensor. Optical rain sensor has a very fast response, minimum maintenance and has a longer lifespan compare to many other types of rain sensing. If you are looking for a simple and hassle-free way to deploy a rain detector, the optical rain sensor is the best option.

The cheapest sensor will be the resistive rain sensor, but it is also the worst in terms of the overall rain sensor comparison.

For a quick comparison of the detection method, check out the rain sensor comparison table at the end of this page.

These are the types of rain detection technologies that are currently available on the market. We will be going through them in the following sections on this page.

Rain Sensor Technologies

Other Rain Sensor Topics

Optical Rain Sensor

The optical rain sensor is by far the best rain sensor available today. It works by detecting the IR light intensity reflected on the transparent top. When the water gets on the surface, some of the lights gets refracted out. Less light gets reflected internally. The reduced in the intensity detected indicates the presence of water.

The rain detection response from this optical rain sensor is fast. The sensor reacts instantly when rain is detected and takes only a few minutes to deactivate after it is clear of rain water.

A hassle-free solution with little maintenance throughout the year. Dirt on the transparent dome surface will not affect its performance significantly, though it is good to have it clean once in a while.

This optical rain sensor is highly recommended for outdoor rain detection installation. Deploy the sensor and you don’t have much to worry much about. The only disadvantage is the high cost compared to the resistive sensor which cost about a few bucks. But if you compare to maintenance cost, manpower cost and time of maintaining a resistive sensor, this sensor is actually quite worth its value.

optical rain sensor
hydreon logo

Optical Rain Sensor

Sensor Specification
Power Supply Input (Voltage):  12 to 30Vdc or 12 to 26Vac
Output Relay:  Normally Open/Close (NO, NC), Max load 1A
Operating Temperature Range:  from -40 to 60°C

Visit our product page for further detailed information about this optical rain sensor,
Or click here for the quick-starter guide for this rain sensor.

Available in Singapore.

You can also buy this Optical Rain Sensor from our online store.

online electronic circuit kit Singapore | PIC-store

1-year warranty for the customer in Singapore.

Resistive Rain Sensor (or Water Sensor)

A resistive rain sensor module is cheap and is a commonly available sensor you can find on the market. The circuit used is often also known as a water detector or a water sensor. It is typically used in detecting rain, detecting water level.

resistive rain sensor
Resistive Water Sensor Kit

fasttech logo

Kemo Rain Detector
Resistive Rain Detector

kemo logo

Velux resistive rain sensor for window automation

Resistive Rain Sensor from VELUX for automated window

VELUX logo

The sensor works base on the resistance of the water. You can visually see the expose copper strips from this sensor. The running copper strip in proximity is exposed on the surface of the PCB board. They look like crossing fingers and basically form two point of contact.

When the sensor is dry, the resistance between both contact is very large (open circuit). When there is water on the surface of the board (touching the expose copper), the water forms a resistive connection across the 2 copper strip. This change in resistance allows the circuit to detect between dry and wet, hence the sensor can detect rain.

This method is cheap and simple. The disadvantage is that the copper in contact with water/air, the copper will get oxidised after a period of time. Performance can change over time (3-12 months depending on the climate condition of your country), therefore it is usually not recommended for industrial deployment use.

In Singapore, such sensor may start to fail in about 3-6 months time, due to our humid weather throughout the year. You just need to maintain the sensor, keeping it clean most of the time, ensuring that it don’t oxidise. If it does, just change to a new sensor board. It is inexpensive sensor anyway.

This rain sensor is easily available from Sim Lim Tower in Singapore.

Check out more other resistive rain sensors here.

Capacitive Rain Sensor

This capacitive has a top plate which detects the change of capacitance when the water is on the plate.

capcitive rain sensor

vaisala logo

Unlike the resistive rain sensor, it does not have exposed electronic parts.

This capacitive rain sensor (Vaisala DRD11A Rain Detector) is available from Vaisala.

Check out this DRD11A Rain Detector user manual (0.19MB).

Mechanical Rain Sensor

This is a very clever design rain sensor from Rain-Bird that uses the principle of mechanical weight to activate a switch inside as a means to detect rain water. A cost effective and robust way of detecting rain. An angled mounting bracket is available to help you mount the sensor on the wall.

Rain Bird Mechanical Rain Sensor SwitchRain Bird Logo

This is how the mechanical rain sensor works. On the top of the sensor cap is some holes which allow the rain water to be collected. Just below the hole inlets are thick board brown-colored rings (like a thick washer) stack on top of one another. Below this stack is a momentary push lever for a mechanical switch.

Normally when there is no rain, these rings are light in weight. The spring from the mechanical switch is strong enough to deactivate the switch. The switch is not activated (in contact), and it simply means that there is no rain water in the sensor.

When it starts to rain, the water will flow down from the hole inlets on top, and pass through the rings. The rain water will get absorb into the ring like a sponge. The stack of rings becomes slightly bigger and heavier in weight. This heavy weight will add pressure to the switch. When enough water gets absorbed and become heavier, the mechanical switch will be trigger, hence indicating that  rain is detected. It will take some time to collect enough rain water for the sensor to be triggered. The rainfall setting can be adjusted via a rotating knob just below the top cap. It basically regulates the flow of the rain water flowing through it, hence control the rate of absorption.

When the rain stops, the stacked rings will begin to dry up, and eventually, after some time, the mechanical switch at the bottom of the sensor will have enough force to deactivate itself. This provides a signal for rain stop. This is a reliable method of detecting rain if the speed of detection is not very important. This is because it takes the stack of rings some time to absorb water and trigger the switch, as well as enough time for the ring to dry up and deactivate the switch.

Rain-bird rain sensor brochure (0.23MB) and user manual (0.6MB) is available here.

You can buy it directly from the rain bird online store.

Car Optical Rain Sensor

Rain sensor onboard luxury cars. They are designed to be small and is usually fitted behind the car’s front window (usually right behind the car’s rear mirror). The working principle is the same as the optical rain sensor above.

Click here for examples of the rain sensor on-board cars, and rain sensor on Mercedes car.

Rain Sensor for Regensensor Volkswagen 1K0-955-559-AH
Regensensor Volkswagen 1K0-955-559-AH

Rain Sensor for Lexus 89941-53020
Lexus 89941-53020

Rain Sensor for Audi Dnaber 8k0955559c
Audi Dnaber 8k0955559c

Rain, Light, Humidity Sensor for Valeo
Rain, Light, Humidity Sensor for Valeo

Rain Sensor for Basyo BY-R606N
Basyo BY-R606N

Rain Sensor for VW Golf MK7 7 8U0 955 559 B
VW Golf MK7 7 8U0 955 559 B

Sound Rain Sensor

This sensor detects the sound of the dropping rain. The rain will hit on the platform which will generate vibration which will be pick up by the sensor.

Rain detector using sound
Using sound to detect rain.

picture was taken from instructables logo

Weather Sensor, Cloud and Rain Detection

This is an advance environmental sensor which can detect the cloud and sky condition. It can also measure wind speed, temperature, etc… This sensor can detect dark cloud and coming rain. It is commonly used for astronomy observatory, to alert the user if there is any bad weather, or automatically trigger the system to close the dome before the rain damage the precision telescope equipment.

Diffraction Limited boltwood cloud sensor
Boltwood Cloud Sensor

diffraction limited logo

The sensor product is not expensive, but compare to the rest of the rain sensors, it is definitely the most advance and expensive weather sensor. This sensor has been deployed at the roof top of Nanyang Polytechnic in Singapore (School of Electronic/Electrical Engineering), to automate the dome system for the astronomy telescope. When it is about to rain, the rain will alert the computer system which will trigger the dome controller to close the dome. This protects the expensive telescope and computer system from the rain.

The system requires some customisation in order integrate to your own automated system. You can contact PIC-CONTROL if you requires such a weather sensor.

Click here for Weather Sensor User Manual (2MB)

Simple Weather Sensor Station

Weather Hawk weather sensor station

WeatherHawk logo

Bloomsky weather station

BloomSky logo

Professional weather station

Aercus logo

Comparison between the Rain Sensors

Click here for a quick comparison between the various types of the rain sensor.

Compare rain sensors technologies

The rain sensor comparison page provides a quick summary of the various types of rain sensors that are discussed on this page.

What We Are Offering

We can custom design rain detection system for your application. You want it wireless, automated, send notification or etc…, they can be done.

Rain sensor helps detect rain, but it does not offer services to notify the neighbourhood.

We are offering a smarter solution that user can subscribe upon for services that can make a positive impact on their lifestyle. A rain problem that becomes easier to manage. Allowing the user to better manage technology and their life.

PIC-CONTROL takes one step further in building up a framework for a smart nation. A smart system that is simple to use and inexpensive cost of ownership through the sharing of resources. A framework that simplified integration for office or home automation control and enables progressive evolution growth.

For further enquiry on a rain sensor automatic notification system, contact PIC-CONTROL today.

Check out other types of electronic sensors for your project installation use.