Arduino Relay Module Bluetooth Upgrade


Introduction: Arduino Relay Module Bluetooth Upgrade

Step 1: How To

Part list:

- 1 channel relay module

- Attiny45/85

- HC-05/06 bluetooth module

- some pin header

- USB mini pcb connector


The attiny program is a little modified arduino SoftwareSerial app.

Its using parseInt, so can receive only integers from the arduino.

In this case turn on the relay when received 111, and turn off, when received 222.

You can change it.

There is many tutorial to attiny arduino programming, including my youtube channel.

Arduino code, android app link in video descrition.

How to:

First, remove the 3 pin terminal from the relay module.

Then solder the mini board to the removed terminal place.

(Im attached only circuit, because too many relay module type, make pcb your own module)

Im used IC holder for attiny if need to reprogram in the future.

Place the attiny to the holder, and the bluetooth module to the pin header.

Power from USB.


You have a small, bluetooth controlled home automation device, to turn on/off anything with android phone.



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    Thank you! I found a cheap one on eBay and in the discriptions its recomended for the iphones :)

    1 reply

    Sounds good. Tell us if working, im curious.

    Cool project! Can I use my iPhone on this?

    1 reply


    I think if you replace the HC-05/06 with a BLE (HM-10) module, an work, but you need an ios bluetooth app. And iphone 4S+