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DUET Signal Reverse Engineering


New Member
I'm trying to develop custom head unit and currently stuck on a DUET protocol implementation.
DUET is used to communicate to iMid, and as far as I know transfer to iMid song/station name, volume change etc.
On schematics it looks just like regular USART signal, just with one additional wire marked as 'control' which seems to be always high when communication is established.
But the data transfered in RX/TX seems to be encoded somehow...
Did anyone already tried to debug it? It seems like there are no information over the internet at all...
Here is a dump I get with my Salae Logic logic analyser. This one is taken from a head unit not connected to the car. Signal on a chanel 0 is coming from head unit when I enable it and seems like a handshake.
View: https://drive.google.com/file/d/1xplXOXf9sS80HEEuASHo4x3HtjlFNlq9/view?usp=sharing

I have an assumption that this might be some sort of Manchester coding, currently investigating this idea.



Well-Known Member
Sorry to bring up a old thread but I was wondering if OP ever made any progress on this?

I'm pretty frustrated by the lack of after market support for the i-mid in the navigation equipped Civics and was considering trying figure out this DUET protocol too.


Toys For Tots
they haven't been online since 2 days after their original post