August 1, 2017 usb relay board

9 USB relay board projects you can make easily

9 USB relay board projects you can make easily

USB relay board is a very useful board if you are considering dwelling yourself in making some home automation projects. To make any computer based automation projects, you need some kind of communication between your pc and the card to the board that is handling the input & output part.

Today we will see some of the projects that you can make using usb relay boards. For these projects, we will be considering two very good usb relay boards – iU-2RD and iU-4RD from iknowvations.

iU-4RD 4 channel usb relay board
iU-4RD 4 channel usb relay board
iU-2RD-2 channel usb relay board










Please note that all the following projects using USB relay board also requires matching any higher level language ( VB, VC, C++, C# etc) based program in PC. Both the boards are having on board relays and analog input & digital input & output pins.

We can connect relays to any electrical equipment to make it ON or OFF while digital & analog inputs are used for connecting various kind of sensors.

Projects using USB Relay board –

1. Automatic light switch.


















This project makes any light On or OFF depending upon certain conditions. For example you want your porch light to come ON when there is enough darkness in evening and be OFF when there is enough sunlight in morning.

You can connect LDR ( light sensor – Light Dependent Resistor) through resistor dividing network and monitor the voltage level through analog input pin of iU-2RD or iU-4RD. The program will monitor the input level which will be high or low depending upon the light falling on the sensor.

Based on this you can take decision if the lights have to be made ON or OFF. And so with the use of relays you can make the porch  light ON or OFF.

You can also make your porch light or any other light ON or OFF based on the time of the day with the help of relay output.

2. Auto presence system.


















Many times when we go out during vacation time, the house remains vacant. If any body observes the house, he / she can come to know that there is nobody in house and may become a target for burgle.

With the help of usb relay board and a small program you can make an auto presence system, which can fool outsider by making 2 or 3 lights of your house automatically ON or OFF during evening & night hours.

This will make anyone believe that there is somebody in house and it is not vacant. You can decide the day and the timings in the program and depending upon it the the lights connected with the usb relay board can be made ON or OFF.

3. Blinking LED through USB.













Well this is a very small & easy project – blinking LED. Though both of the usb relay board are having on board user LED which can be made ON or OFF simply by sending command LED1 to make it ON or LED0 to make it off. Making it ON or OFF repeatedly in program providing some suitable delay in between will make the user LED blink.

You can also connect LED to any digital output pin and blink it using output high & low commands.

4. Temperature controller.















You can connect any temperature sensor that provides analog output to the board’s analog input pin to monitor temperature. Using this property, you can make temperature controller yourself.

For example you want a system, where the temperature is maintained at 25 degree centigrade. Just connect any suitable temperature sensor like LM35 or similar to analog input pin. Monitor the analog output level in program and based on this you can make fan or Heater ON/OFF through on board relays.

5. Home alarm system.












Connect some magnetic switches & PIR sensors to digital inputs  and a hooter to the relay output. Voila ! you have got a Home Alarm system. Yes, with the help of these few things and usb relay board, you can make a Home Alarm System yourself within no time.

The magnetic & PIR sensors will help you to monitor any intrusion through doors & windows and the hooter will make a big sound when any kind of intrusion is attempted.

6. Digital Water Meter.













Do you want to have an eye on your water usage ? Want to have an early warning when you cross a particular water consumption ? Then, this is a perfect evening project for you to make.

Grab yourself a water flow sensor. when you connect this flow sensor to your main water inlet line, you will get pulses at the sensor output which will be proportional to your water usage. Connect this to digital input of usb io board, write a small program monitoring the pulses input and there ! you have made a Digital water meter !

7. Aquarium controller.


















The automation system of your aquarium will not only keep your fishes very happy but you also as it will relieve yourself of daily routines of feeding & maintaining of oxygen level & temperature of the water, feeding the fishes and keeping the water clean.

All of these can be done with the use of usb relay board and a small program in your PC. The temperature sensor can be connected to analog input of the board and the pump and the feeding system and be connected to the on board relays.


8. Auto sprinkler system.

















Maintaining your garden requires proper care and your precious time. Many times, it is not possible to spend time in your garden due to various reasons like Not well, gone for vacation, out of the town, very busy in day to day work etc.

During these periods, if you are having a system that can take care of your garden, the garden will not suffer any damage due to non care. The usb relay board connected pump can water your garden at pre defined time regularly.

Not only this but you can also add soil moisture sensor to measure the moisture in garden soil and based on this it will water the garden.

So now keeping your garden lush green is a not a headache !

9.Decorative Light pattern generator.



















There are many times when we decorate our home with many different colored lights & LED bulbs like Birthday parties, during Christmas and the festivals, wedding anniversaries etc.

How about adding some variations in lighting ? We are attracted to moving things much more than a steady thing. Moving light patterns will attract more to your guests rather than steady lights.

You can connect these lights through usb relay board relays and make them ON one by one adding some delays in between. This will create different light patterns as per your choice. This will not only be more attractive but you can have many unique patterns that your guests may not have seen any where else.

In coming days we will show exactly in detail, how all these projects can be made. So watch out this space regularly.

So go genius ! Grab a usb relay board & unleash your creativity ! And yes, we are there to help you in case you have any difficulty. just contact our support team at and they will be more than happy to turn your idea into a successful project.




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