I'd like to join this conversation with similar question related to powering the Core2/Tough (AXP on board).
What will happen if with "enabled M-bus 5V output" we will charge the system with external power connected to 5V pin on M-bus? Is it possible to set on battery charge when "output" is enabled?
That can happen when you are using Tough and external power source f.ex. via RS485 socket (on Tough it's mounted DC/DC buck converter that is powering the system via 5V pin on M-bus socket).
I assume that AXP192 is not managing the "hot-swap" and we can expect some strange results when 5v pin on M-bus (pin 31 named VBUS on AXP192 chip) is powered from "onboard 5V Booster" and from external DC/DC buck converter that is mounted on Tough.EXT module/board.
Reason for questioning:
I'm using Tough witch internal battery and 5V units connected via Grove socket. I need to power the units all the time. When "enable M-Bus 5V ouput" is active, than battery charging is not active when M5Stack Tough is powered from Tough DC/DC converter (green RS485 socket). So, I need to set "M-Bus output" disable. But then when the external power is off, the 5V booser is not working, so the unit is loosing power. I was trying to implement "hot-swap" procedure in code, but time of switch was too long to get it flawlessly.
Looking for help ...