You can heat it with a hair dryer to melt the glue a bit. This allows easy removal of the screen structure without damage.

You can refer to the sequence from left to right TXD RXD IO0 RST GND 3.3V to use other serial port modules for programming.

You can heat it with a hair dryer to melt the glue a bit. This allows easy removal of the screen structure without damage.

@ajlenze Only ESP32 can be found in the Arduino Boards Manager. You need to install ESP32. And C3 is a derivative of ESP32. After installing ESP32, you can select the C3 subclass chip in the board

Steps:

1. Use tweezers to short IO9 to GND (because ESP32C3 already has firmware by default, it needs to enter BOOT state)
2. Link USB (note that the positive and negative plugs select ESP32C3)
3. Normal upload procedure

The AT firmware should work with all ESP32-C3 products.
Firmware link:
https://docs.espressif.com/projects/espat/en/latest/esp32c3/AT_Binary_Lists/ESP32-C3_AT_binaries.html

Upload method:https://docs.espressif.com/projects/espat/en/latest/esp32c3/Get_Started/Downloading_guide.html

I don't know if the font format of U8G2 is consistent with that of GXEPD. It is recommended that you refer to the font modification of GXEPD, which indicates that it is a subclass of Adafruit_GFX.
Link: https://github.com/ZinggJM/GxEPD

For 3-5 first display updates the time string is printed weakly, how can I fix it? I use the code from official sample.
-> Refresh the area multiple times to deepen the color, or use full screen refresh.
Which batteries can I use with this module?
How can I check the battery charge level and charging status?
->The module is equipped with a 1.25 pitch battery interface, which can be powered by batteries
How can I turn off the red blinking led?
->The red LED is the battery indicator, flashes when there is no battery.
Is there any other recommendation for power-save?
->Hibernate enters deep sleep. The deep sleep power consumption reaches about 10uA

You can refer to the sequence from left to right TXD RXD IO0 RST GND 3.3V to use other serial port modules for programming.

Currently T-Watch does not have this function, we will refer to your opinions so that we will create new products that can meet this requirement in the future.

I don't quite understand what you mean, is it that ESP32 uses BLE to communicate with the mobile APP? If yes, this will involve communication protocol issues

@yakuzja There are two ways to get started quickly

1. Use the Arduino IDE and install the ESP32 support package.
2. Use the VSCODE PIO plug-in, this plug-in can automatically configure the environment for you, the compilation speed is relatively fast, and it also supports Arduino functions and libraries