$15 Car Stereo Bluetooth Upgrade

We’ve seen all sorts of ways to implement Bluetooth connectivity on your car stereo, but [Tony’s] hack may be the cheapest and easiest way yet. The above-featured Bluetooth receiver is a measly $15 over at Amazon (actually $7.50 today—it’s Cyber Monday after all) and couldn’t be any more hacker-friendly. It features a headphone jack for plugging into your car’s AUX port and is powered via USB.

[Tony] didn’t want the receiver clunking around in the console, though, so he cracked it open and went about integrating it directly by soldering the appropriate USB pins to 5V and GND on the stereo. There was just one catch: the stereo had no AUX input. [Tony] needed to rig his own, so he hijacked the CD player’s left and right audio channels (read about it in his other post), which he then soldered to the audio output of the Bluetooth device. After shoving all the bits back into the dashboard, [Tony] just needed to fool his stereo into thinking a CD was playing, so he burned a disc with 10 hours of silence to spin while the tunes play wirelessly. Nice!

29 thoughts on “$15 Car Stereo Bluetooth Upgrade

    1. description on amazon item linked says: “FINIGO NFC-enabled Bluetooth 4.0 Audio Receiver with APTX Technology for Home Stereo for car”. still, airplay/dnla would be better/higher quality.

  1. this one DOES support apt-x:


    I have it and while it mostly works, pairing it is a huge PITA. if you have a phone with a display, fine, life is good. but if you are trying to pair 2 dongles and neither have a display, knowing when they are paired is nearly impossible. I did it once with 2 such dongles (sender and receiver) with intention to use it in the car, but its very ‘blind’ and not user friendly. the receive mode of that avantree unit works ok but in transmit mode, it times out too easily (on song silence) and then you have to power it on again, manually.

    would be nice to have dongles like this but with pairing indicators. have not found such a thing.

    1. blackberry music gateway will solve that for you. pairs to any phone or device, is no bigger than that, powered by usb. supports two devices at once and is nfc enable with the codec you are seeking.

        1. The last bluetooth adapter I bought was a nightmare to connect every time: it would stay paired with my phone, but would time out and go to deep sleep if I forgot to enable BT on my phone. Does the BlackBerry constantly seek your phone, or do you have to choose it from the phone?

  2. i bought one of the pictured audio receiver from eBay for just a couple of bucks, but mine sounds like sh1t.
    there’s absolutely no bass in the audio signal. no matter what i connect it to, even a pair of decent bookshelf speakers hooked on to a 20W amp chirp like a mobile phone in a can.

    not to mention the 2-3m effective range.

    that’s why i rather built a “shairport express” from a tplink mr3020 and an usb sound card. takes 20-30 seconds to boot, but the sound quality is quite nice, even if i use just a junk $0.99 usb sound card.
    basically the AR9331 in the router has I2s connectivity, but those pins are not accessible.

    1. I had the range problem with mine, and blame it on the short internal antenna. If my basic radio skills haven’t failed me, a better antenna length is near 2.5 inches. I soldered a piece of wire of that length to the on board antenna of several of these, and have seen reliable ranges of between 5 and 20 meters, even though walls now. Not sure if it increased the audio quality but I suspect it’s a bit better now.

  3. While this counts as a great hack, it provides me the opportunity to rant orthogonally :-)

    Where are the cheap bluetooth-audio-receiver-fm-transmitter bridge devices? If you look around online, you can find a few, but I have only seen one in a store in Canada – and it was $100 (ie not cheap).

    Lots of bluetooth receivers that plug into stereos with audio in. Lots of FM transmitters that plug into your mp3 player. Marrying them seems to make perfect sense.

    1. Unfortunately, I think there might not be enough of a market for them to warrant mass production. FM transmitters are typically used in cars that are new enough not to have a tape deck, but old enough not to have an aux in jack, so probably three or four model years.

      However, they seem like they’d be simple enough devices. Maybe it’s an untapped market for some enterprising tinkerer to explore.

    2. I’ve done that, cheap FM transmitter that plugs into an MP3 player headphone jack, cheap Bluetooth receiver that you plug headphones into, less than $20 Canadian and I can play my phone over my car radio via Blufum (or whatever the hell you call a Bluetooth to FM adapter setup.)

    1. neat trick, if you care about the laser assembly you may have concern that the laser will wear prematurely as the laser has to continuously re-focus in order to find the track it will never find on the top of the disc..

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