Tiny drone

Some time ago I bought, mostly out of curiosity, a tiny drone from verkkokauppa.com, named RedBird Nano Cam. It wasn't too expensive, but then again, it isn't too great at flight either - fairly unstable and hard to direct even in best circumstances.

Here's the thing, without propellers (rotors?), with two euro coin to give  a bit of size reference. Although the bird on top looks quite blue to me...

It got some abuse too, in the twitchy hands of kids, so it got dropped often. So I guess it was to be expected that it would be short-lived toy. And eventually it did stop charging. Best guess, kid left it on and that killed the battery dead.

So what a curious engineer does when that happens? Yes, break out trusty tools to see what's inside...

Top cover off at this point, and I had already done some damage by not noticing four screws that  keep top and bottom covers together. D'oh. Nevertheless, the green board is the camera module, connected to main board only with only three wires. Interesting.

Camera module off, it wasn't even glued or taped down. Camera module also has place for MicroSD card it.
On the main board there are three main chips;

Invensense MPU-6050C - combined gyroscope/accelerometer module, apparently one that is very widely used. I've been considering using similar chip for one application I've been thinking about, but unfortunately I haven't found suitable gyroscope yet - for the application I'm thinking about I'd need around +/- 10000 degrees/sec operating range, but most seem to be around +/- 2000 degrees/sec range - this one included. Not even close to sufficient.

ST Micro STM32F031K4 processor.

XN297, a 2.4GHz transceiver chip.

The other side. In corners there are motor driver transistors, and in middle a clock crystal and few programming test points. All in all, quite simple thing.

I tried measuring the battery, and it read exactly zero. When trying to charge it, voltage rises to about 0,2v. It's dead, and I don't feel like trying to figure out why either (earlier speculation aside) Might as well get rid of it, except that fun-looking camera module ... I can think a few uses for it immediately.