Saturday, May 17, 2014

Working bluetooth prototype!

Here's my working prototype bluetooth module. I'm using the BC05B bluetooth module, which works great.

It still has a lot of bugs, and I may have to redesign/add some things.


  1. steering wheel controls for next track & beginning of song/previous track!
  2. 1 device for bluetooth audio/control; NO WIRES!
  3. sound quality is very good (IMHO)
  4. module connects to the last-known-connected device automatically, if it's within range (i.e., if my iPhone 5 was the last device that the module was connected to before I left the car, when I return to the car, it automatically connects when I'm back within range)
  5. when switching to aux mode, the currently connected device starts playing automatically
  6. when switching to radio mode, the currently playing, connected device stops playing (hits the pause button for you so you don't "lose your place" in the track)

  1. The volume turns on at medium; i'm trying to get the device to turn the volume up full at power on but no luck yet
  2. still not 100% sure on the pairing sequence for to this module:

  • pairing a new-to-the-module device
  • pairing a new-to-the-module device when the module is currently connected to a different device
  • connecting a known device to the module
  • connecting a known device to the module when the module is currently connected to a diff device

No artist/track info available yet (that i'm aware of) for displaying on the SID; will look into this after I get all the other bugs worked out.

The bottom of my pcb is my attempt to get the volume to turn up at power on, but it's not working, I think because of software...could be the 4066 chip I piggy-backed on top of the other :)

Right now, I have the SRC button on the steering wheel set to put the module into discoverable mode (this only works if you're in Aux/CD changer mode, so you can still use SRC to change between FM1, FM2, and AM1). This has worked pretty good so far between switching connected devices; i.e., when my wife wants to play her music through the car, I hit the SRC button while playing my music, it disconnects from my phone, stops the music [the head unit kicks out of aux mode, back to the radio], the module goes into discoverable mode, she connects to it, and I hit CD twice to get back to aux mode, and it automatically starts playing the last thing she was listening to.

enough talk, pictures!


  1. For Sale!?!?!?!?! I would Love to buy one of these from you! What are you asking for one for an 03 9-5? This is the best Aux in set up i have seen for these SAABs! Thanks -Will

  2. Hi,

    I also would love to buy one of these for my 2007 Saab 9-5.
    Please contact me by email

    Have a nice day!
    Best regards,

  3. Hello,

    I would also be interested in buying a complete unit if it works with my 2000 Saab 9-3 convertible.


  4. Where can i buy one Aux/bluetooth adapter too saab 9-3og?


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