I'm noticing that even with the example sketch (https://github.com/m5stack/M5Atom/tree/master/examples/ATOM_BASE/ATOM_Motion) the two motors (pins M1, M2) turn inconsistently. Sometimes a positive speed (+100) will result in motion, and likewise with a negative speed (-100). But just as often the write will result in a high-pitched tone from the motor, but no motion. Writing zero always stops both motors. Has anyone else experienced this, and can you offer any insight/ideas?

I notice that these function, and several others, are commented out in the current M5Stack GitHub repository. (See M5Display.h) Before I do too much experimentation, does anyone know if these functions are intentionally deprecated for this device, any if so, why?