battery_level.ino

batetry_level.ino

#include <M5StickCPlus.h>

// the setup routine runs once when M5StickC starts up
void setup() {
  
  // initialize the M5StickC object
  M5.begin();

  // Lcd display
  M5.Lcd.fillScreen(WHITE);
  delay(500);
  M5.Lcd.fillScreen(RED);
  delay(500);
  M5.Lcd.fillScreen(GREEN);
  delay(500);
  M5.Lcd.fillScreen(BLUE);
  delay(500);
  M5.Lcd.fillScreen(BLACK);
  delay(500);

}

// the loop routine runs over and over again forever
void loop(){

  // text print
  M5.Lcd.fillScreen(BLACK);
  M5.Lcd.setCursor(0, 10);
  M5.Lcd.setTextColor(WHITE);
  M5.Lcd.setRotation(3);
  M5.Lcd.setTextSize(4);
  
  M5.Lcd.printf("%.0f%%", getBatteryLevel());

  // wake up after 60 seconds
  esp_sleep_enable_timer_wakeup(60000000); 
  // start deep sleep. Display goes out!
  esp_deep_sleep_start();  
 
}

double getBatteryLevel(void)
{
  uint16_t vbatData = M5.Axp.GetVbatData();
  double vbat = vbatData * 1.1 / 1000;
  return 100.0 * ((vbat - 3.0) / (4.07 - 3.0));
}