Hi, I would not recommend powering through Vin with a battery and USB at the same time. As the 5V from the USB will start charging your battery connected on Vin. When connecting to the battery terminal, there is a detection circuit that switches the power source of Vin between USB and battery to not put 5V on the battery lines.

Just to give feedback, I've had the Pytrack + Gpy powered via the VUSB_AUX for a few hours and all is working fine. Thank you for all the help!

@KiraKiraSoul said in Expansion Board 3.0 Vin (3.5-5.5V) pin: In other words, is the input voltage regulated in any way on the expansion board? No. It's the same signal, just differently labeled. When connected to USB, you should see 5V at that pin coming from USB. Otherwise you can supply a xxPy device at that pin with input voltages from 3.5-5.5 V.

@SiMoS-IoT Thanks. Given the state of Pycom documentation and the large quantities we are going to need we have decided to build our own solution, so the power feed issue will go away. I really like the approach to power Pycom have, but the fact we can't get any documentation on how it functions, other than a few system calls, means we can't take it into production. I'll probably still keep using it, but only for interests sake.

To close this post, I wanted to say that the issues I found in the deep sleep shield, have already been reported before in this forum. My mistake was not to do an exhaustive search before posting. Conclusion: the deep sleep shield has quite a few problems when powered by a lipo battery. *bradnz hace 12 meses For any one interested, or has this issue in the future I have resolved this by doing the following: Rolled back firmware to 1.7.9.b3 Used version 1.0.0 of the deepsleep.py file from github. Works fine now.* post1 post2 post3

@andreas said in ADC use to measure battery level / Vin level: We are getting reasonable readings when using the 1 MΩ / 1 MΩ values as resistor values (matching v3.2) @MKO just measured the resistor values and confirmed [1] that it's also 1 MΩ / 1 MΩ for the Pycom Expansion Board v3.1, as supposed. [1] https://community.hiveeyes.org/t/batterieuberwachung-voltage-divider-und-attenuation-fur-microypthon-firmware/2128/42