USB Power Good LED not always illuminating?

Brendon

We've got some devices out in the field and have suddenly started noticing connection problems over the J9 connector. One clue is that the D2 "USB Power Good" doesn't always illuminate and that seems to correspond with a failure to be able to communicate with the board over ADB or using a network dongle.

Any suggestions as to what we can check to what is going wrong?

Could this be a software problem, or hardware?

Thanks.

Moderator

@Brendon could be overheating? can you watch voxl-cpu-monitor?

Vinny

HI @Brendon
J9 and that LED are "mostly" independent.
J9 is our USB-C port, whereas that LED is indicating the VBUS power is present for J3 USB host port.

There are several things that might make this LED turn off:

SW control, using GPIO_157. That controls the power switch for J3, so if that is set LOW, it will disable the VBUS on J3.
J3 is only able to source ~900mA max current. If you are indeed using J3 and not J9, please check your device is not pulling too much current. If you are using an actual 1S battery, as the voltage drops, so will the current capabilities. So, if you are pulling too much, you are putting a droop into the VBUS. If you are running a fan on 5V and a magnetometer unit at 5V, that also takes away from the max capability as listed here: https://docs.modalai.com/voxl2-mini-connectors/#power-inputoutput-important-note
If you are loosing ADB, that is indicative of a board reset or a short on the USB-C port. This is where the Moderator's comments come into play as well. Clearly a reset will cycle power on both J9 USB-C and J3 USB Host ports. A short on USB-C may force the power mgmt chips to cycle power as well.

Are you able to send a picture of your setup, including your power supply to VOXL 2 Mini? That will help us guide you further.

Thanks!