M680 with aftermarket headunit

[vecais_dumais_laacis]

Hi. Maybe it is useful for someone like me. 

 

I swapped headunit on 996 with PCM1, DSP and M680 (nokia) amplifier. Then i found out amplifier does not work without proper signal from headunit.

I made simple hardware that tells amplifier to turn on max volume. That allows to use aftermarket headunit with line out.

 

For hardware i used attiny85 board - digispark ( probably chinese clone as there are no proper markings on board ). It is 5V microcontroller. Amplifier expects 5v serial signal ( 9bits + 1stop bit 19200baud rate )

 

Full code - https://pastebin.com/N3PG4Rqe

Hex firmware for attiny85 attached.

 

Can be done with different mcu. Bytes to send are visible in source.

 

DigisparkDSP.hex

[gizlaroc]

Nice job man! 

This will be a bit of a lifesaver for many, means a nice double din can go in while keeping the oem amp and speakers. 

[dvdbck]

Hello, I made a renntech account specifically to respond to this post.

I have the same issue, installed an aftermarket head unit and have an M680 amplifier. I am new to microcontrollers but am willing to give this a shot. Could you elaborate on how the microcontroller was installed?