Proffie Board hot w/SD card

I am new to the Proffie board (it is v2.2, white, from Darkwolf), and want to make sure the board itself is working before doing too much wiring. I installed the latest version of the ProffieOS and have nothing hooked to the board. (No battery, no neopixels, …) With an SD Card in the slot, the board gets hot and the board says the battery voltage is ~5V. Without the SD Card in the slot, the board does not get hot and the board says the battery voltage is ~1.9 - 1.67 volts.

I assume that the board should NOT get hot with an SD card in the slot when nothing is hooked up? So likely have a short on the board? I found a crack in the SD card itself.

Looking at the schematic, it seems the board will always try to use a battery to pump up to 5V, not switch between the USB and battery (like an Adafruit board would). So I assume that reading a battery voltage of ~1.67 is okay without a battery?


Where are you measuring?
The 5v booster is only activated when there’s battery voltage.
You should have a solid 3.3V on the 3.3V pad and SD power pads when on USB only.

@NoSloppy I should have been clearer in my post - the voltage reading is what is being reported over the serial port by the ProffieOS, which matches what the Batt+ pad is. The 3.3V line is a solid 3.3V.

I think things are all good as I don’t have the battery hooked up yet, but the board appears to be functioning. Now on to the actual soldering …