Hello,
after my glorious throttle mod I also came across a quite dirty but cheap CH Combat Stick game port version... So I made a plan to turn it into USB using once more the MMJoy arduino path.
I took an arduino sparkfun pro micro and the MMjoy firmware, another MCP-3208 ADC for the stick axes and wired up everything in the base. While in the CH Pro Throttle game port version the poti had idk like 100 Ohms or something and needed an additional resistor before the MCP-3208 input to keep it from freaking out, the Combat Stick came with high resistance potis (100k?) and that way was ready out of the box for the modding.
Meanwhile I also took apart the grip, and threw all the plastic pieces into the dishwasher (ymmv) to remove ten years of somebody else's palm sweat and grease residue (eew).
I think that's the early version of a Combat Stick as the gimbal springs are tiny. In the original setup, the 14 or so grip buttons are all wired down into the base individually; I decided to use an array of shift registers in the grip to reduce the length of the wiring significantly. So after all this, a mere 5 wires (VCC, GND, DATA, CS and CLK) were left, plus one empty I was too lazy to pull out of the cable assembly. Note I marked which colour means what on the base before closing it, and of course not without testing everything with the help of some cheap breakout 74HC165 shift registers and a breadboard.
Also note the mega unprofessional use of red/black wire for ground and white/black for VCC
For the grip, the Combat Stick I had came with two hats and two buttons at the top thumb area (trim, sensor select, pickle and perhaps sensor select down for the AV8BNA), and a single button on the thumbrest halfway down the stick. On the box, there is a version pictured that has one of the hat switches in that position, and the button moved up to the main area.
Now I still had a spare hat switch from my CH Pro Throttle, the index finger one to be precise, which I had replaced with an analogue stick mod by the mighty @rel4y.
I decided that this needs to go into the thumbrest, increasing the actual number of buttons on the stick to 17. It required some grinding to fit into the button well, as the Throttle variant came with a square PCB while the CH Fighterstick variant that fits the same spot does not have a PCB but directly connects the microswitches. The rest is exactly fitting, including the little notch that prevents the hat switch from turning in its round socket.
I tried fitting 3 x 74HC165 shift register breakout boards in, plus the necessary pullup resistor networks - which had to be SIL because my SMD soldering capability is not existing. Of course I failed miserably, but I came across a very nice 3 x 4021 shift register SMD setup on ebay classifieds. And, shame on me, until I read his name on the PCB when it arrived yesterday, I had failed to realize that the guy selling it was in fact our very own @rel4y. Hi mate, thank you for doing this!
From then on everything was really just plug-and-play, also switching from 74HC165 to 4021 shift registers was as easy as 1 2 3.
Cramming all that into the stick handle was still a nightmare, but at that point I could also no longer be asked to reduce the truly excessive wire lengths. To make everything fit, also around all the different studs and screw wells, I had to bend one of the pin header arrangements on the shift registers to 90 degrees inwards, but then *** ta-daaaa *** everything closed nicely, snapped into place and works like a charm. The only thing now is, I am missing a rudder axis dearly, especially for the half-helicopter AV8BNA. Perhaps that's my next mod? Who knows
