Project RAUX Box Update

"Future Heap Owner" (aperiodic)
04/07/2019 at 18:10 • Filed to: Project RAUX Box, Pupper, Electronics

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:

Sorry for the blur. The only non-blurry photos of her face I’ve been able to take are when she’s asleep

DISCUSSION (11)

AestheticsInMotion > Future Heap Owner
04/07/2019 at 18:34

Is this all just for a n aux port?

Future Heap Owner > AestheticsInMotion
04/07/2019 at 18:50

Yup!

I could just pay $300 for it, but where’s the fun in that?

LOREM IPSUM > Future Heap Owner
04/07/2019 at 19:05

If you’re sure you are never going to need to service it, epoxy might be a good option . Ju st make sure whichever one you use is non-conductive.

AestheticsInMotion > Future Heap Owner
04/07/2019 at 19:25

$300 is nuts. Any cheap way to add Bluetooth capabilites while you're doing this?

Future Heap Owner > AestheticsInMotion
04/07/2019 at 19:41

Yeah, it’s actually easier to find audio chips that take input over Bluetooth than it is to find ones with aux input! The guy on s wedespeed who did this first switched over to Bluetooth for input after the proof of concept. So adding that would only be another $10-15 bucks (maybe less), though a nontrivial amount of work.

But honestly, I don’t even want Bluetooth. I primarily want to plug in my iPod Classic, which only has a headphone jack. Maybe sometimes I’ll plug in my phone for a podcast, but my phone still has a headphone jack. I don’t want to answer calls while driving. Adding Bluetooth would only make it easier for passengers to play their own music; I’d prefer for them to find something they like on my iPod (which has a lot of music across many genres).

AestheticsInMotion > Future Heap Owner
04/07/2019 at 21:26

So would the ipod be tucked away somewhere in the car? I’ve gotten so used to being wireless I could never go back...

Turn the car on, put the phone in the mount and boom. Automatically connects to Bluetooth and starts playing music, in addition to wireless charging. Pulls up Google driving as well, since I like having a map to check traffic/accidents/etc.

Future Heap Owner > AestheticsInMotion
04/08/2019 at 01:23

Well I’m also a paranoid loony with a long-ass cell phone password with special characters, so driving stuff off my phone is not that convenient for me.

My plan is to run an aux cable down to the little cubby behind the floating center stack, so it’s a bit out of the way, but easily accessible when it’s time to change albums.

AestheticsInMotion > Future Heap Owner
04/08/2019 at 01:34

Oh god. We’re complete opposites. My phone has no lock screen whatsoever. Not even a swipe! Gives my cyber security friend major anxiety lol.

I can’t wait to check out your Volvo sometime.

Future Heap Owner > AestheticsInMotion
04/08/2019 at 01:40

Are you planning on coming to the cruise?

AestheticsInMotion > Future Heap Owner
04/08/2019 at 01:54

Kind of up in the air right now. I'm hoping I can make it

Future Heap Owner > AestheticsInMotion
04/08/2019 at 02:17

Makes sense given your current situation . I hope you can too!

If not, I’ll at least be passing through the Seattle area on the afternoon of the Friday before (the 10th).