After some testing I decided to use ESP32 board with
since it has a lot of nice neatures that will be useful like:
Normal ESP32 is a bit too big for ozobot, so I bought ESP32-C3-MINI-1 based board. It's nice, but with full ESP32 forth it leaves only 17% of memory left. If I understand specs correctly, that is roughly 65KB. Lets hope it is enough for some lignt forth experimentation and I will still probably want to add some sd card. Also I can always try to remove parts of system that I don't need, but I'd prefer not to.
Next knowlage learned is that I apparently need some sort of driver to control the motors. This driver also needs some other board to transform voltage. Since this all can't fit inside ozobots head, I had melted extra hole on the front to fit the driver.
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