08-21-2017, 06:11 AM
Ah OK, I see where you're pointing at 
So if I get this straight, this jumper controls whether the vcc-5v is connected directly to the microusb 5v power supply or an upconverted 3.7V supply from the battery. So if I was powering this from DC, cutting the connection J9, 1, 2 would cut power to the 5V power rail, and so the USB devices.
I'm still not sure I understand completely, but staring at it helps. Thank you.
One further question (that makes me suspect I do not understand). The schematic also says "Note: When using DC 5V and battery supply together, Disconnect J9 1, 2, 3, 4" How in this case is the right voltage supplied to the USB power rail?
So if I get this straight, this jumper controls whether the vcc-5v is connected directly to the microusb 5v power supply or an upconverted 3.7V supply from the battery. So if I was powering this from DC, cutting the connection J9, 1, 2 would cut power to the 5V power rail, and so the USB devices.
I'm still not sure I understand completely, but staring at it helps. Thank you.
One further question (that makes me suspect I do not understand). The schematic also says "Note: When using DC 5V and battery supply together, Disconnect J9 1, 2, 3, 4" How in this case is the right voltage supplied to the USB power rail?