Thanks, Terry. I had much the same thought.

Using the method from the GetBatteryVoltage sketch I saw an overlap between the power measured without a battery and that when a small lipo was connected, so voltage doesn't seem to be a very good discriminator.

Interestingly the battery connected (and fully charged) voltage was up to 4808mv, higher than the no battery voltage of 4768-4778mv.
Any such voltage is a disaster if applied to a single cell lipo. Maybe it'll burst out the back of the case ...

Henry

It would be great to get a definitive response from the LilyGo team because the work-around could be a bit painful.

My thought is that if USB power cannot be determined directly, perhaps it can be inferred from some period of declining voltage.

Any other ideas?

Thanks, Terry. I had much the same thought.

Using the method from the GetBatteryVoltage sketch I saw an overlap between the power measured without a battery and that when a small lipo was connected, so voltage doesn't seem to be a very good discriminator.

Interestingly the battery connected (and fully charged) voltage was up to 4808mv, higher than the no battery voltage of 4768-4778mv.
Any such voltage is a disaster if applied to a single cell lipo. Maybe it'll burst out the back of the case ...

Henry

I am building firmware for the T-Display-S3 which needs to behave differently when connected to mains power (via USB) versus when on battery. I have not yet found an API or method that I can use to distinguish between the two.
My objective is to conserve power when the device is unplugged.
To be clear, the hardware has built-in behavior which turns off the display when it's unplugged unless GPIO 15 has been asserted, but this doesn't save enough power and I don't know how I can tell when this has happened. What I'd like to do is to put the device into light sleep mode when it's unplugged. Light sleep works fine, but I can't tell when the device has been unplugged.
Any thoughts on detecting the unplug event?