Hello @wjcarpenter

the battery charging IC is TP4057 and battery voltage is measured via R40 / R41 into GPI38. See second page of the schematics here.

Thanks
Felix

@Wizzy38952 Have you charged it?
Erase bruce and only burn UIFLOW2

@ajb2k3 Thanks for the reply. Maybe I'm misunderstanding what the Vbus is supposed to be. I thought it was the power coming in from the USB port. Even if there is a trickle of stuff draining the battery, there shouldn't be any input from USB. I suppose something is just leaking over somehow.

Yes, this is a common issue with M5Stick C flashing. Try holding the G0 button while connecting the USB cable to enter bootloader mode, then start the flash. Also, double-check your USB drivers and try a different USB port directly on your PC (avoid hubs). If problems persist, adding a 10µF capacitor between EN and GND can help stabilize the reset line. Make sure the serial port is correctly selected, and close other apps using it. This usually resolves the “Failed to connect to ESP32” errors.

It sounds like the battery may be dead or disconnected internally. Warning 22 usually points to a battery issue. Since it powers on with USB but not on its own, try opening the case carefully and checking the battery connection. If that looks fine, the battery might need replacing. You could also try a full reset by holding the power button for 6–10 seconds.

@coolman861263
Please follow this instruction and see if helps:

Observe whether there are any obvious physical damage marks on the device. Install the device driver: Windows: https://m5stack.oss-cn-shenzhen.aliyuncs.com/resource/drivers/CH9102_VCP_SER_Windows.exe macOS: https://m5stack.oss-cn-shenzhen.aliyuncs.com/resource/drivers/CH9102_VCP_MacOS_v1.7.zip Connect the device using a USB cable and open the device manager. Check whether the device manager page refreshes when the device is inserted, and whether a new device appears in Universal Serial Bus controllers. If not: If you are using USB C to C cable: First disconnect the StickCPlus, turn off the device, and then plug in the cable (press and hold the power button until the green light turns on to indicate that it is turned off). Or replace it with an A to C cable. If you are using USB A to C cable: "Try to change the data cable", "Try to reinstall the driver", "Try to change the PC". Reburn the factory firmware: https://docs.m5stack.com/en/guide/restore_factory/m5stickc_plus. The screen is still black after burning: Press and hold the leftmost button until the green light inside turns on, then plug in the USB cable Observe whether the screen is black but has a faint backlight, and whether there is a beep sound when pressing the button

Still no Mic in 2025, in UIFlow2!

In my case I was able to overcome the issue by configuring a DNS resolver and uploading the code via USB

import network # set CloudFlare DNS resolver network.ipconfig(dns="1.1.1.1")

Hello @xxx_yyy

I stand corrected. My apologies. You are absolutely correct: IMU INT in M5StickCPlus2 is not connected to anything. (I was looking at the RTC INT.)

That said - and to answer your original question - yes, it is possible to connect the IMU INT pin to an ESP32 GPIO. Please see here.

However it would only allow to wake ESP32 from deep/light sleep, but not to turn M5StickCPlus2 back on from being powered off due to the fact that IMU is powered from 3.3 V (and not like RTC from VBAT_IN).

Thanks
Felix

@mali-draper use M5burner and load latest firmware for M5StickCPlus

for start install M5Burner,
connect your M5StickCP2 via usb to pc/laptop and observe if it will detect com port,
from M5Burner you can then load latest firmware for your device.

I bought and tested an I/O expansion unit called U011-B.

As a result, I was able to successfully read four I/O signals from the M5StickC Plus from U011-B during using WiFi.

@xter-pokemon Allways erase before burning, and triple check you have the correct version of the firmware for the correct controller version.

@felmue Works for me too!
I never thought of that for StickCPlus2 !!!
Thanks