External power to header ?

[DrWino]

Need to connect 5V power direct to header and remove battery. No clear what header pin to connect to - 5V ?, BAT ? or the mysterious HPWR pins ? Anybody tried this yet ? Thanks.

[X-Dron]

1. The easiest is to use the USB cable and connect the 5V to it.
   2.If you do not need a battery, you can connect to pin 5 on the bus.
   3.I'm going to use such a power scheme. Red lines are new wires.
   HPWR is not used in M5Stack now. it is presented only on the bus.
   

[DrWino]

@x-dron I guess you mean connect to the 5V not pin 5. Pin 5 is GND. What happens if power is supplied to 5V pin and then you connect USB at same time for programming - I suppose you could make a special USB programming cable with the USB 5V disconnected.

[X-Dron]

@drwino
I'm sorry for missprint. Of course pin "5V". :)
I said the best and most problemless way is to use the usb connector of M5Stack. You could make a special USB cable only with 5V.
All other methods have nuances.
See M5-Core-Schematic.
The simplified power scheme looks like this.

VCC_5V, VCC_3V3, Vbat are connected to the bus, V_USB is not.
if you connect external power to VCC_5V then

• A special USB programming cable with the USB 5V disconnected 'll not work. Course CP2104 is not powered.
• If you want to program simply turn off the external power supply 5V. For example to use a jumper.
• You can try to use a diode. But I do not have confidence.
• The battery is not charged.
  
  I want to connect external 5V power to the V_USB wire and remove the USB-fuse.
  In this case all will powered and 5V from the USB is disconnected. Battery works too.
  All must have a common GND.

[DrWino]

Thank you for the detailed reply. I will try some of the options but first I will order a few M5Stacks so life can continue if we get blue smoke !

[X-Dron]

@drwino
:-)
Good luck.