Very cool hack in the classic DIY spirit from Hackaday:
Since you’re going to have to be flying your “drones” indoors anyway in the USA, at least in the US Capitol region, you might as well celebrate the one freedom you still have — the freedom to re-flash the firmware!
The Eachine H8 is a typical-looking mini-quadcopter of the kind that sell for under $20. Inside, the whole show is powered by an ARM Cortex-M3 processor, with the programming pins easily visible. Who could resist? [garagedrone] takes you through a step-by-step guide to re-flashing the device with a custom firmware to enable acrobatics, or simply to tweak the throttle-to-engine-speed mapping for the quad. We had no idea folks were doing this.
Spoiler alert: re-flashing the firmware is trivial. Hook up an ARM SWD programmer (like the ST-Link V2) and you’re done. Wow. All you need is firmware.
The firmware comes from [silverxxx], and he’s written all about it on the forum at RCGroups.com. He’s even got thecode up on GitHub if you’re interested in taking a peek. It looks like it’d be fun to start playing around with the control algorithms. Next step, Skynet!
Reading the forum post, it looks like you’ll have to be a little careful to get the right model quad, so look before you leap. But for the price, you can also afford to mess up once. Heck, at that price you could throw away the motors and you’d have a tricked-out ARM dev kit.
And if you insist on hacking everything, you can probably re-purpose a wireless mouse controller to control the thing. Write your own code for the controller and you’ve got an end-to-end open firmware quadcopter for a pittance.