Sep 11, 2014

Bluetooth Remote for 2 Relays

Successfully create a circuit for controlling to relays from Android device. The load can be anything with power consumption less than 100W. Well, the relay can handle 10Amp but the PCB is not designed for that capacity. Tiny 5V 200mA PSU is used to power the whole circuit, relays and MCU consume 20mA each, bluetooth module consumes 38 mA while waiting for connection and 8mA when connected.

The language is simple,
"L1=1" for turning on 1st relay.
"L1=0" for turning off 1st relay.
"L2=1" for turning on 2nd relay.
"L2=0" for turning off 2nd relay.

I use bluescript android apps which you can download here
I modified the permission to access SD card in the code since it doesn't work with my Android 4.4.2.
The code is available at

The schematic:

Here below the MCU code:

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