If you’re interested in connecting the PS3 Keypad to your Raspberry Pi, I’ve found a way to do so using the QtSixA project. Note that the process is a little bit easier if you’re using RetroPie 2.3.
In the case you are using RetroPie 2.3, simply install the PS3 controller driver using the RetroPie Setup script (/home/pi/RetroPie-Setup/retropie_setup.sh). If you happen have a PS3 controller, now would be a good time to set that up. This step is important because it will install the necessary libraries for you to compile the sixpair-kbd executable, which you’ll need to pair with the PS3 Keypad. Next, you’ll need to download the sixpair-kbd.c file from the QtSixA project:
$ cd /home/pi/RetroPie-Setup/tmp/build/ps3controller $ wget https://raw.githubusercontent.com/falkTX/qtsixa/master/utils/sixpair_kbd.c $ sudo gcc -o sixpair-kbd sixpair_kbd.c -lusb
This should create a sixpair-kbd executable in the /home/pi/RetroPie-Setup/tmp/build/ps3controller directory. You should then copy this file over to the opt folder:
$ cp /home/pi/RetroPie-Setup/tmp/build/ps3controller/sixpair-kbd /opt/retropie/supplementary/ps3controller/sixpair-kbd
Next, simply make sure the power switch for your PS3 Keypad is in the off position, attach it to your Raspberry Pi via a USB cable and run the above executable:
$ sudo /opt/retropie/supplementary/ps3controller/sixpair-kbd
Once it pairs, you can disconnect the PS3 Keypad and turn it on and it should be connected over Bluetooth (you may have to tap on a key on the keypad)!
Now, if you don’t have RetroPie, you can follow these instructions to get QtSixA installed on your Raspberry Pi. Once you’ve completed that guide, follow the above guide to pair your PS3 Keypad.
Enjoy!