I have some dfrobot firebeetle M0 dev-boards from an earlier NeoPixel project. They come with SPI-based 12MB extra flash-memory, which was a good thing for NeoPixel animations.
Would it make sense to use flash-based lookup tables for sin/cos/atan stuff to speed up the control loop?
PS: I also like these boards, because they have the extra developers playground onboard.
The only reason, why I picked ESP32 for my first sFOC project was the slow 48MHz vs 240MHz clockspeed.
12MB is quite a bit for a MCU.
You could use it to store some calibration data, but the question is how quickly data can be loaded from the memory. If you need several extra SPI calls per loop iteration I don’t think it will be good for performance…
Sin/cos already use a lookup table, it only needs a few hundred bytes though
There may be a significant amount of low level stuff you have to get working all over again if you switch MCUs. Timer stuff or whatever. It’s surprising how much things can be ported over from one mcu to another, but it’s not going to be everything you need, probably.