@vintageslots The factory test code reads the voltage. https://github.com/Xinyuan-LilyGO/TTGO-T-Display/blob/master/TFT_eSPI/examples/FactoryTest/FactoryTest.ino

@alveron Sometimes...this depends on the sketch that is running and other Arduino environment conditions...you need to manually enter Upload Mode.
Press both Reset and Boot and release the reset first. You will lose the Arduino serial com and you need to re-select it.
Once you have a stable environment it may not require the sequence, just Upload!
You must select USB CDC On Boot: "Enabled" to get serial from your sketch to your computer.
ADC in ESP32 is very poor. I don't have a T7-S3 to test, just check the Diagram and other Internet sources. There will be data noise and poor accuracy.

@hosky well, you could use the esp32 built in ADC to read pin 4 bat volt, or wire the 5V pin to a voltage divider and then to a GPIO, such as 16 and digitalRead it.

@lewis - No I have not. Definitely looks promising though. I'll see if I can get it working on a couple different ESP32s. Thanks! I knew I wasn't the first one to ever think this capability up.

@etolocka Well, Ernesto, if the returned value is saying that the battery is 100% of 4.2 volts...I think you are THERE!
I do not use Python, have a board like yours or ever monitored battery voltage, so I am no expert, it looks like you are OK!
-Terry

@vitorxlima Easy! Put a diode in series with the non-rechargeable battery to allow the battery to dis-charge and run the board but not allow the USB to pass current to it.

@zhang-lilygo As VID we could use USB_VID = 0x2E8A (that's the Raspberry Pi foundation) and simply need to request a new PID in the Google form, linked in https://github.com/raspberrypi/usb-pid . But this has to be done by the Lilygo company. Can someone from Lilygo please request this PID? We have a post from https://github.com/Xinyuan-LilyGO/LILYGO-T-display-RP2040/issues/5 that the request was done in May 24, 2022. But no PID so far.

Can someone from Lilygo request the PID again? And a second one for the T-PicoC3? The board description is complete and working with Circuitpython 8.1.0 but it is not published because the PID is missing.

@rcarteraz As VID we could use USB_VID = 0x2E8A (that's the Raspberry Pi foundation) and simply need to request a new PID in the Google form, linked in https://github.com/raspberrypi/usb-pid . But this has to be done by the Lilygo company. Can someone from Lilygo please request this PID? We have a post from https://github.com/Xinyuan-LilyGO/LILYGO-T-display-RP2040/issues/5 that the request was done in May 24, 2022. But no PID so far.

Can someone from Lilygo request the PID again? And a second one for the T-PicoC3? The board description is complete and working with Circuitpython 8.1.0 but it is not published because the PID is missing.

@whippe Interesting!
hmmm...I am way out of my depth here.
The PeakCan seems to be CAN to USB.
Do you have an example sketch to base this on?
The ESP32 connects to which end, the USB or CAN?
Does the equipment offer automotive style OBDII communication?
If you have the time, I'd like to know!