Just got my M5Paper these days and was playing with it, measuring the power consumption, figuring out the best way to approach writing a low power application for it. I really love the form factor and the capabilities. Figured out how to send esp32 in deep sleep and wake it via touch gestures (using doze mode).
I disconnected the internal battery and connected a lab power supply (4.2V) and tested the calculator app (while idling - no touch events, no screen updates)
- 169 mA - with the default app
- 93 mA - with EPD power disabled
My question is: why does the EPD consume so much power (almost half!) while the screen is idle? I was expecting it to be close to nothing.
Do I have a defective unit? Or can this be optimized in the EPD driver?