Work on Project RAUX Box has slowed due to being busy with the new pupper, but in the past few days I have managed to make a small amount of progress.
I’ve soldered header pins on to my Arduino clone and the audio board, figured out which pins I need to connect between the two for the I2C comms and which ones will carry the digital audio output signal, and got them all hooked with a breadboard:
Though I just realized that I forgot to put in power & digital ground wires on the audio board 😑
The audio board is too big to fit on my breadboard, so I had to solder it to a proto board, solder the jumper wires in, and then connect the jumper wires and header pins underneath:
This is janky as all heck, but it’ll do for now. Once I’m sure these are correct, I’ll probably take the similarly janky step of covering these underside wires in hot glue for insulation (I’m open to better ideas here).
I’ve also spent some time with the audio chip’s datasheet and started to figure out some of the configuration values I’ll need to set for it to output in exactly the I2S format the Volvo’s head unit expects:
But there’s a bunch of power and audio path configuration I’ll need to figure out, too. I’m hoping to get all that figured out by the end of this week, then program it all in the Arduino next weekend. At that point, I should be able to use my logic analyzer to verify the digital audio output is working, which will be a big milestone!
Bonus pupper pic for you nerds/compulsive post readers that made it to the end: