Introduction: DIY Bluetooth MicroPCI Express From Cheap £1 USB Adapter.
This is my first instructable, It might be useful for other members looking to make their own cheap Bluetooth solution for their laptop.
Some people may be thinking, why not just use the dongle in the USB socket instead of going to all this trouble?
All I'll say is that I don't think having 'temporary solutions plugged into USB's', I wanted something which would also have superior range as well as being hidden away. Most laptop's have a spare MicroPCI Express slot and most of the time will have a spare antenna cable, either for Wi-Fi or Bluetooth, both will work fine, Wi-Fi and BT are both 2.4GHz.
Plus, you get the pleasure of making and actually using something cool (mine connects to my Bluetooth sound system in the house).
For this you will need;
an old PCI Express Micro or Mini card,
A Heat gun or SMT rework station,
Cheap £1 USB Bluetooth dongle
Some Wire (enameled wire from an old motor is ideal)
Soldering iron and basic hand tools (screwdrivers etc).
First, clear all of the components from the old WiFi Card, this may need a fair amount of heat, but try to avoid damaging the antenna connector, you'll probably want to re-use this.
Attach the Bluetooth dongle to the donor card, I soldered the 0v pin of the USB to the groundplane of the donor card.
A 3.3v line can be found on pin 52, it will likely already have a track running from it.
The 0v line is pretty much anywhere on the outside edge of the card.
Once the BT dongle is attached, wire the 3.3v line to the point shown in the picture, not to the 5v pin on the USB connector!
The reason for this is that the BT dongle has a 3.3v regulator on the board, since you already have a 3.3v supply and don't have a 5v supply, you can just use this attached to the appropriate place.
Here is the pinout of the MicroPCI Express card, you will notice that USB_D+ and - are on pins 38 and 36, these won't usually have traces connected to them on the card as not many use the USB lines, this is why thin magnet wire is ideal in this situation.
This shows the connections to the USB pins, I used tape to insulate the wire from the PCB, you won't necessarily have to do this but I did just because I didn't want to damage my laptop if it went wrong and shorted out.
Run the wires (gold coloured wires in the picture) to the USB D+ and D- pins, D+ is the one next to the GND pin, the D- pin is next to the 5V pin.
You can leave the original antenna intact, but the signal is rubbish. So, wire the antenna to the antenna socket and plug in an antenna, however you might want to use a blocking capacitor (or leave one on the original card and wire to this, instead of directly to the socket) as I didn't and nearly killed the BT dongle (it wasn't even recognised by windows).
This is the final step! If you've got everything correct then you will be able to plug it in, switch on and it will work. Before you do, make sure you test the connection between the 3.3v line and Ground, if it's a short circuit, then you've done something wrong.
Congratulations and enjoy your new cheap wireless solution!
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