Reply to t-deck Battery Indicator on Mon, 12 Jun 2023 19:33:05 GMT

abdnatsheh — Mon, 12 Jun 2023 19:33:05 GMT

thanks for your reply !

Reply to t-deck Battery Indicator on Tue, 13 Jun 2023 00:20:09 GMT

teastain2 — Tue, 13 Jun 2023 00:20:09 GMT

@abdnatsheh I don't have a T-Deck, but this works on my LilyGO T-Display S3

Add these lines:

#define BAT_ADC_PIN 4
and the the loop:
  uint32_t voltage = readAdcVoltage(BAT_ADC_PIN) * 2;
  tft.setCursor(50, 70, 4);  //add correct offsets as required for your board
  tft.setTextColor(TFT_RED);
  tft.fillRect(42, 70, 70, 25, TFT_BLACK);//add correct offsets as required
  tft.print(((float)voltage/1000) +0.32);

The ESP32 has a notoriously bad ADC with linearity and offset issues, so this reading cannot be used for scientific observations, only a relative health check.
Also when the USB is hooked up the Battery charge voltage is 5V !!!
You can only see the battery when USB is unplugged.
Hope this helps
-Terry