Chibios DRV8835 Driver

I bought two DRV8835 dual motor driver break-outs recently. When I looked at the aforementioned link, I figured I'd made a mistake: using the full feature set requires 4 PWM outputs, and looks rather complicated. However, I had an STM32F100 board, and with one of these, it actually turns out to be easy: You need one timer, but each timer has 4 channels. You can get the board from Farnell for £6.19 at the time of writing.

In fact what drew me to these in the first place: being tiny, and having high sustained current (1.2A per channel) still holds, and these are great little modules.

That does leave me with some problems though: specifically, the micro controller boards (and all the cheap STM32 eval boards) have no mounting holes. I think I've found a locally sourced solution to this as well: PCB card guide. I still need some angle or something to attach this to, so it's still a lot more bother than just screwing it on some stand-offs, but once I have some angle the right size, cutting off a length and drilling some screw holes in it won't take long.

All these posts seem to end up full of links to places to buy things in the UK, but that's part of the point. It often takes me ages to stumble on a place to buy the right components. I might write an article just on suppliers and what to find there some when.

Example source code can be found here.


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