Sunday, March 2, 2014

How to build your own 3.5mm version of BlueSaab

I get a lot of emails from people on how to build one of these things so here are directions. This involves soldering through-hole components and uploading code to the microprocessor with Arduino.

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.
  1. flash the bootloader if necessary (I'm not going to cover how to do that here; google it)
  2. Assemble the PCB
  3. Wire up the 3.5mm jack to the PCB with ~5" of wire for each pole
  4. Cut a hole in the enclosure for the CD changer connector and a 1/4" hole for the panel-mount 3.5mm jack.
  5. upload the code with an FTDI adapter/cable
  6. plug it into the cd changer harness (using the adapter cable, if necessary for 9-5 people)
  7. 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.


  1. Very nice guide! A problem is that i don't have access to "The code".
    Kind regards

    EDIT: Newermind, found it! Thx!

  2. Awesome project and guide!!!
    I assembled the 3.5mm version of BlueSaab but actual I have the problem that I'm not shure about the CAN library I found for the Arduino. Where do I get the library? Because the Atmega is working with the code (sends the Serial.println commands) but its not communicating with the CAN and therefore also not communicating with the car (nothing happens by pressing the CD button). Please could you help me here or contact me?

    1. Se4587 at Y! Or G mail and I'll get you the lib :)

  3. Hi at first i have to say Great work!

    This version also supports iPhone music controls via the steering wheel controls; play/pause, next track, & previous track. BUT this requires that you run another wire (maybe 2?) from this module to the iPhone, to a 30 pin iPod connector. Yes, you can use a 30 pin to Lightning cable adapter & it will work for iPhone 5.

    Being that this module plugs into the trunk mounted cd changer plug, you'll need to route this cable/cables from the trunk to the front if the car, along the door sill & under the carpet, behind the dash, etc. Not terribly hard, just takes a little time. I suggest either a 25' 3.5mm stereo male to male cable for audio only, or maybe an Ethernet cable for audio & iPod controls.

    How do i get the connection from iphon/ipod to pcb? which contacts?

    On the pcb are several polarity signs missing. The capacitor C8 has a different build directen in your picture as on the PCB.. which is the right position?

    Do you know a way to order the cdc connector from germany? connectorppl wont ship to here..

    sry for my bad english :/

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