$12 Bluetooth Upgrade

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.

Those are:

LM7805CV 5V linear regulator

.01uF caps(2 pcs)

47uF Electrolytic Cap

1A 5x20 fuse and holder

RS project case

RS protoboard

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........