Bela Gem Power Pin When Using USB WIFI Dongle?

violapwr

I'm using a Bela Gem with RTL8188CUS WiFi dongle but when powering the Bela over battery the dongle does not work. However, it works fine when powering over the Bela's USB connection. The battery I'm using is more than capable (2200 mAh and 50C discharge) and my buck converter can handle up to 4 amps.

I'm using P1.01 for external power injection. On my old Bela Mini, I used P1.05 successfully for the same setup without issues. Are there significant differences in how P1.01 vs P1.05 power the USB subsystem?

giuliomoro

Powering is exactly the same as on BelaMini: if you want USB host port to work, you should power via P1.07, as that's what's giving power to the USB port. I should clarify that in the documentation.

giuliomoro

As before, you should not have power into P1.07 when the board is connected via USB to a host, or the two 5V source will fight each other.

violapwr

great - this works. thank you!

giuliomoro

Additionally, if you use a Schottky diode from P1.01 t to P1.07, you should have USB power while providing 5V into P1.01, without having conflicts when connecting the USB-C cable.