I came up with this project because a colleague of mine wanted an easy way to control his three garage ports, so I thought it would be nice to control it with an Android app via Bluetooth.

I started by building a prototype on a breadboard. I used an HC-06 Bluetooth module for the connection with an Android device. Because I didn't need that many pins, I used an ATtiny85 to control everything. The Bluetooth module uses two pins on the attiny so I have three pins left as outputs. These three outputs are used to drive relays. Everything is powered with 3.3 V because the bluetooth module only works with 3.3 V.

To control the relays I made an app in Android Studio. With this app you can pulse or toggle the outputs. When pulsing the outputs, the pulse duration can be set from 0.1s to 5s in steps of 0.1s.

Now I'm going to put everything on the Elektor-Labs Prototype Board ELPB-NG.

The project is built on the Elektor-Labs Prototype board. For the relays I used UA2-5NU signal relays.

Because we liked the project, we also made a special PCB for it. This PCB and the programmed controller is available in our Elektor shop.