I went back home just before the summer and when I got there I was doing a lot of driving. I have a couple of RF adapters in my car to plug in my phone and ipod, and I got to thinking. I have been working with micro controllers this year, and I bet there is a way for me to clean up all of the wires in my truck by using an arduino and bluetooth. So when I returned to NY, I started looking online for a tutorial that might make it possible to make a bluetooth audio receiver that I could plug into the aux jack in my truck. It turns out that the way that data is transferred with bluetooth and the memory constraints of arduino, it was not possible. Undeterred I kept looking for a way to make this happen. Ultimately I came across a surface mount chip called an RN-52, which is a bluetooth digital audio receiver chip. Sparkfun sells the chip as surface mount and also with a breakout board, and has a tutorial for exactly what I need.
Sparkfun’s tutorial utilizes all of the features of the chip, data in/out, and sound. I am only interested in utilizing the sound for my device, I can make changes such as volume up and down, track back and forth, etc on my phone which rides in its holder in my car. I am only interested in getting the audio to stream to a 3.5mm jack so I can plug it into my car stereo receiver.
The parts list for this device is the rn-52 breakout board, and a basic 3.3v breakout board to manage the power.
Here is the schematic and the proposed changes to suit my needs. I will use a arduino pro mini for the serial UART as a substitution for the sparkfun UART.