I've been using a wired aux in connection in my car or a while. I'm just too cheap to upgrade my radio.
I decided to cut that cord and still not spend too much. I was going to use a little bluetooth module in a cigarette lighter to usb adapter but then I'd have to deal with people asking "whats that?". I decided to hide it under the dash instead.
I bought a lot of the parts at the local Radio Shack Super Sale. The Bluetooth module was $3.68 on ebay...
Step 1: The Bluetooth Module
First thing is to carefully pry it open and remove the board. I used a small RS project box. It easily fits all the components I'll need.
LM7805CV 5V linear regulator
.01uF caps(2 pcs)
47uF Electrolytic Cap
1A 5x20 fuse and holder
RS project case
Step 2: Fitting the Module to the Box
I drilled a hole for the audio in as close to the bottom as possible. Then I removed the ribs so the jack would fit as close as possible to the wall.
This made the outside perfectly flush...
Step 3: Freebie Heatsink
RS gives you two covers. One plastic and one aluminum. I drilled out the holes in the aluminum cover to fit around the posts of the plastic cover.
This way I could sandwich the two together. I mounted the regulator to the plate with a generous blob of heatsink compound and a small 4-40 screw/nut. Once cleaned up and trimmed down it fits nicely between the two covers.
I folded a small section of the bottom edge over to route the wires from the regulator.
Step 4: Final Assembly
I mounted all the parts on a small protoboard. See Fritzing schematic....
I used a USB socket I had salvaged from a hub to connect to the audio module.
I mounted the USB socket with a BIG blob of hot glue where is would apply enough pressure against the audio jack to keep the module in place without any other mounting. Just in case I ever want to reuse that module....
Step 5: Testing and Use
I hid everything behind the glove box and used the blue power antenna wire from the radio for power. This way it only powers on with the radio.
The module I got plays and audio clip that says "bluetooth ready" on power up. It lets everyone know I upgraded.
Now I can leave my phone in my pocket rather than have it floating around the dash while I'm driving........