@eifel69
I was able to see the clock lettering (Alivaba font) by opening up the ESPTouch app and passing my WiFi credentials while the FACTORY was loaded in my T-Display-S3.

My favorite YouTuber Volos has a good video where he covers how to use custom fonts.
https://youtu.be/R-qFKemDFyM

This is part 3, so it’s also worth reviewing parts 1 and 2. Hope that helps.

UPDATE: Just realized my clock is an hour off. Hope your results are better.

@giulio-buccini
FYI I had similar problems and when I got it figured out I made this GitHub repository:
https://github.com/teastainGit/LilyGO-T-display-S3-setup-and-examples
Please download the repo and read everything(!) and especially study the screenshot that shows the Arduino Board upload menu.
https://github.com/teastainGit/LilyGO-T-display-S3-setup-and-examples/blob/main/ArduinoBoardSelection.png

@fabryz OK, I gave it more thought and your problem may be that you have a program construct like "while true Serial.print(somevariable)" that needs to serial print and receive a confirmation.

Please post your program for further assistance.
-Terry

Can you say more specifically what is wrong?
I do not understand the image that you sent.
I can usually help with T-Display S3/ Arduino IDE issues!
-Terry

@aardvarx55 Hi!
On the Boards Selection did you set USB CDC On Boot: "Enabled" ?
And you say you set output 15, LCD Control "ON", not related to serial, but things that screwed me up at first!

@metawops I have no idea what the factory sketch is supposed to do!
Thats why I made my HotHead example, to debug and get it running.
I studied the code and made the Hothead tempsensor and a FPS version (not included in the repository that I posted) to determine Frames Per Second.
I also added the LCD backlight ON command to HotHead, after both displays "went dead". This revived them.
The factory tft.ino included in the factory download just shows you how to learn the tft.drawsprite and sprite.drawString functions, with examples.
If the LilyGO is really stuck you can try the black reset button on the back and/or the "left" (when holding it vertical with the USB down) button marked "BOT" (boot) in various combinations to clear it
-Terry

I have an example using MicroPython before, but using ESP32, they are all driven by the built-in SPI module of MicroPython, you should modify the pins slightly and it should work fine

https://github.com/lewisxhe/mPython_ST7789

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

Hello , here is the driver link for reference :

https://github.com/Xinyuan-LilyGO/CH9102_Mac_Driver
https://github.com/Xinyuan-LilyGO/CH9102_Driver

Hello @dabee , Is the new battery suitable for the product ? If still have any other questions, please contact us without hesitation .

Hello, the code has been fixed. The ESP32 Pico option is available.