Buy the parts here (~$40) or anywhere else you find similar stuff:
If something is out of stock, you'll either have to wait for more to be ordered or delete it from your cart and buy a suitable substitute. i.e., sometimes the atmega328p is out of stock so I order the atmega328.
If you don't want to buy the blank atmega328 chip, you can pay extra for a 328 with a bootloader preinstalled ($5):
Buy one of these ($5):
Buy a CD changer connector ($7/ea, minimum 2, plus S/H: ~$20):
Order the PCB (minimum quantity 3, for $30 shipped):
It takes about 3 weeks for them to get fabbed and shipped.
You'll also need/want 4 screws to hold the PCB to the enclosure; I use 4, 5/16" panhead screws.
I also secure the CD changer connector to the PCB with 1/2" long 4/40 panhead screws and 4/40 locknuts.
- flash the bootloader if necessary (I'm not going to cover how to do that here; google it)
- Assemble the PCB
- Wire up the 3.5mm jack to the PCB with ~5" of wire for each pole
- Cut a hole in the enclosure for the CD changer connector and a 1/4" hole for the panel-mount 3.5mm jack.
- upload the code with an FTDI adapter/cable
- plug it into the cd changer harness (using the adapter cable, if necessary for 9-5 people)
- route the 3.5mm cable from the module to the front of the car under the carpet/door sills
You'll probably have to contact me regarding flashing the code...just FYI ;)
To get to the aux in on the head unit, hit the CD button twice. If you have a tape player and cd player (9-5 people), hit CD 3 times. You can also hit SRC button on the steering wheel to cycle.
With the minimum quantity orders for some of these items, it's probably a good idea to get together with another Saab buddy and just build 2 or 3 of them.