I have multiple goals for this project. The main objective, is learning by doing. But there are other good side effects. I have a cheap SBC with Batocera Linux on it. And we play retro games with it. Why not add a retro gamepad, too, for additional nostalgia?

So far, I've bought a broken old Sega. These are found easily in the country from second hand markets. The mainboard didn't have much to offer. However, it has got a pair of gamepads. The chassis, buttons and rubber pads are useful.

So far, I have dimensions of the PCB written down. The PCB I make should have almost the same dimensions.

The other thing left, is choice of SoC. I'll have to find an off shelf Lithium Battery to power it. And I don't think any battery will simply fit in the chassis. So the SoC plus the wireless connectivity shouldn't drain too much power. What I have in mind is a 300-400 mAh battery which is quite easy to find in the country for like 1-3 USD.

I've got two choices in mind:

 - ESP32-C3 + Bluetooth. And then it'll be a bluetooth gamepad. I really doubt if it'll be efficient enough to run for few hours on that battery. However, I have ordered a development board to see how much the actual power consumption will be.

 - STM32F1 + 2.4Ghz tranceiver IC. The disadvantage is that I will have to craft a USB dongle for it as well. Advantage of STM32F1 is USB support. And for sure the power consumption will be MUCH lower. I have Ci24R1 in mind as the wireless IC. It's so cheap and available in the country.

There are, of course, other choices. But the two above have quite decent Rust support, and are also available in the country. I'm afraid I can't go down the route of importing components, especially now when the country is in war.