@oroppas
Have you changed any settings on the display? In other words, did you do anything special before this problem occurred? Did the problem develop gradually or suddenly? Does the screen behave the same way when you flash other firmware?
Providing more detailed information would be very helpful to our product.

@amudon
sudo apt-update は成功しますか?

Hello @kimtommy

hmm, works for me. Tested both: power off and deep sleep.

I created an example which might help you. You can find it in the UIFlow2 Project Zone: M5CoreInk_PowerOff_DeepSleep_Test_UIFlow2.3.2

Thanks
Felix

Hello @GermanSheepDog

below is an alternative function which works for me too:

#define PI4IOE5V6408_ADDR 0x43
#define OUTPUT_REG 0x05

void my_set_backlight(bool o) {
  uint8_t data = M5.In_I2C.readRegister8(PI4IOE5V6408_ADDR, OUTPUT_REG, 200000);
  if(o == true) data |= 0b10000000;
  else data &= ~0b10000000;
  M5.In_I2C.writeRegister8(PI4IOE5V6408_ADDR, OUTPUT_REG, data, 200000);
}

Thanks
Felix

Hello @GermanSheepDog

your my_set_backlight() function works for me and my_set_backlight(true) turns the backlight off (inverted logic).

void my_set_backlight(bool o) {
  PI4IOE5V6408_Class p;
  // false input, true output
  p.setDirection(7, true);
  // false off, true on ?
  p.digitalWrite(7, o);
}
void setup()
{
  auto cfg = M5.config();
  cfg.serial_baudrate = 115200;
  M5.begin(cfg);
  M5StamPLC.begin();
}
void loop()
{
  M5.update();
  if(M5.BtnA.wasClicked() == true)
  {
    Serial.println("BtnA clicked - backlight on");
    my_set_backlight(false);
  }
  if(M5.BtnC.wasClicked() == true)
  {
    Serial.println("BtnC clicked - backlight off");
    my_set_backlight(true);
  }
}

Thanks
Felix

P.S. the AI generated code did not work for me.

Hello @clydeps

I don't know the pitch of the connector. However my M5Tab5 came with a matching cable. Maybe double-check your box?

Thanks
Felix

@SparklesForever
what is "yellow M5 little block sensor" specified?

@maby2001
If you use a Roller485, you can connect directly to PortA of the Core2 to provide power + I2C control at the same time.

Yes, you can use the 485 bus to provide power and I2C control at the same time.

@Jomac Are you putting the Cardputer into Firmware mode but holding G0 while plugging in?

@oracle_sod I think this may be connected to an error I found.
set up a basic "Hello world" example and check the terminal. I was getting MQTT server errors with basic code because M5Stack are using MQTT for pushing programs from the UIFLow server to the cores.