The topic says it all. This is (obviously) not to show off any special skills, I just wanted to quickly build something really cheap and did not want to pay 60 bucks or more on an Airturn or Blueturn. Here is how I did it, in case somebody is looking for something similar, this will save you a lot of time for reverse engineering the keypad logic...
Start with this keypad (only the packaging is left...):
(https://i.postimg.cc/B6rfWqQX/Verpackung.jpg)
Remove the keypad from the main PCB (you can slide it out or simply cut the transparent "cable")
(https://i.postimg.cc/nh38FKh8/IMG-20190825-120139.jpg)
(https://i.postimg.cc/6pWJxbwL/IMG-20190825-135038.jpg)
Cut off the plastic enclosure below the battery compartment (already glued in the enclosure and wired in the picture)
(https://i.postimg.cc/Mpk5MfgH/IMG-20190829-075431.jpg)
Solder wires to the PCB to the connections A3, A6, B5, B10, B15. I chose the following colours:
A3=White
A6=Brown
B5=Yellow
B10=Grey
B15=Orange
For the offboard wiring, the following connections send the corresponding keypress:
A6-B15="6/go right" (brown/orange in my build)
A6-B5="4/go left" (Brown/yellow in my build)
A3-B10="Bluetooth connect" (white/grey in my build)
A3-B5="Toogle Num Lock" (white/yellow in my build)
The last two are only needed to bind the pedal to a new tablet/notebook/mobile phone or to change to cursor mode, should the device ever come up with num-lock activated (it actually has not so far...)
The back lid allows for access to the batteries and the on/off switch:
(https://i.postimg.cc/gkL42HS1/IMG-20190829-075407.jpg)
The front side could not be more "Quick and Dirty DIY":
(https://i.postimg.cc/59RnJR3w/IMG-20190829-075353.jpg)
Cool project!
Ahhh, now how to fit it into the Eoo3...