Predictably enough, the “couple hours” I thought it would take to transfer my circuit over to the proto boards and add relays ended up being closer to five, so that’s all I managed to do over the weekend.
In the photo, the larger boards in the back are the control board with Arduino and level shifter on the left, and audio board on the right. The small things in front with the yellow boxes are the relays that will select which audio is being fed into the head unit; the pins in the front are where the existing ribbon cable will need to be spliced in. The grey cables heading out of the frame on the right are the audio hookups for the AUX port.
These three audio cables from the AUX port were particularly difficult to solder due to their larger thickness and the tight spacing for these inputs on the audio board. In the development phase, I used jumper wires and ran the audio path through the breadboard, and the sound quality was awful (more noise than music). I’m hoping the time I spent to get these cables to fit pays off.
The next step is installation! If I finish some other errands quickly enough, I hope to pull the stereo and disassemble to it find the ribbon cable tonight. Maybe I’ll be able to solder the ribbon cable in too and have everything ready to test tomorrow night.
I’m starting to run right up against my deadline. If it doesn’t just work once I hook everything up, I doubt I’ll have time to do very much debugging. And I don’t have a good idea of how to permanently install everything if it does work; hopefully there’ll be enough room behind the stereo to fit everything and I’ll be able to drill a small hole in the glove box for the aux port, but I might have to redo all the wires between the main boards and the relays to make them longer so I can put the main boards in the glove box.
Wish me luck!