Also have you guys experimented with the difference between
M5.Axp.DeepSleep();
and
esp_deep_sleep_start();?

AFAIU Axp.DeepSleep is only supposed to turn off "external devices" (gyro, screen, etc.) but not the ESP itself, right?

And @Morris45 what does the Wire.begin(32, 33); line do in your code above? And why are we commenting out M5.begin()? What's the battery life you're getting from your watch? I'm trying to do a simple infrared remote (that only wakes up when you first pres the main button) and even in full deep sleep, I'm only getting 2 days.

Using the sleep.ino in the examples in Arduino IDE with M5StickC library installed I've confirmed this:

When the device goes into light sleep it draws 6mA

when it goes into deepsleep it draws 2mA

however if I press the power button just once, in deepsleep it draws 25mA for that loop of the program, once you press button A again the current consumption returns to 2mA in deepsleep.

However, when I run the program for using my M5StickC as a smart watch, when in deepsleep it draws 2mA in deepsleep like normal UNTIL I press the power button just once. If I do that, it draws 16mA in deepsleep! The only way to stop it doing this is to press the power button for 6 seconds to turn it off, and then press the power button once more. If I do that, it goes back to drawing 2mA in sleep once again.

Do you have any idea what's causing this?

Here's my code:

#include <M5StickC.h>

RTC_TimeTypeDef RTC_TimeStruct;
RTC_DateTypeDef RTC_DateStruct;


uint8_t led_count = 15;
long brightnessTime, tiltTime = 0, tiltTime2 = 0;
float b, c = 0;
int battery = 0;

float accX = 0;
float accY = 0;
float accZ = 0;


#define TFT_GREY 0x5AEB

float sx = 0, sy = 1, mx = 1, my = 0, hx = -1, hy = 0;    // Saved H, M, S x & y multipliers
float sdeg = 0, mdeg = 0, hdeg = 0;
uint16_t osx = 120, osy = 120, omx = 120, omy = 120, ohx = 120, ohy = 120; // Saved H, M, S x & y coords
uint16_t x0 = 0, x1 = 0, yy0 = 0, yy1 = 0;
uint32_t targetTime = 0;                    // for next 1 second timeout

static uint8_t conv2d(const char* p); // Forward declaration needed for IDE 1.6.x

uint8_t hh, mm, ss, YY, MM, DD, dd;

boolean initial = 1;

void setup() {
  //COMMENT next line after first upload

  M5.begin();
//  Wire.begin(32, 33);
  pinMode(M5_BUTTON_HOME, INPUT);
  pinMode(M5_BUTTON_RST, INPUT);
  pinMode(M5_BUTTON_HOME, INPUT_PULLUP);
  pinMode(33, OUTPUT);

  esp_sleep_enable_ext0_wakeup(GPIO_NUM_37, 0); //1 = High, 0 = Low

  //COMMENT next 12 lines after first upload
  
  hh = conv2d(__TIME__), mm = conv2d(__TIME__ + 3), ss = conv2d(__TIME__ + 6); // Get H, M, S from compile time
  RTC_TimeTypeDef TimeStruct;
  TimeStruct.Hours   = 23;
  TimeStruct.Minutes = 10;
  TimeStruct.Seconds = 30;
  M5.Rtc.SetTime(&TimeStruct);
  RTC_DateTypeDef DateStruct;
  DateStruct.WeekDay = 6;
  DateStruct.Month = 06;
  DateStruct.Date = 12;
  DateStruct.Year = 2020;
  M5.Rtc.SetData(&DateStruct);
  
  //COMMENT UPTO HERE

  M5.Rtc.GetTime(&RTC_TimeStruct);
  hh = RTC_TimeStruct.Hours;
  mm = RTC_TimeStruct.Minutes;
  ss = RTC_TimeStruct.Seconds;

  M5.Rtc.GetData(&RTC_DateStruct);
  YY = RTC_DateStruct.Year;
  MM = RTC_DateStruct.Month;
  DD = RTC_DateStruct.Date;
  dd = RTC_DateStruct.WeekDay;

  M5.Lcd.setRotation(1);
  M5.Lcd.fillScreen(TFT_GREY);

  M5.Lcd.setTextColor(TFT_WHITE, TFT_GREY);  // Adding a background colour erases previous text automatically

  // Draw clock face
  M5.Lcd.fillCircle(40, 40, 40, TFT_BLACK);
  M5.Lcd.fillCircle(40, 40, 36, TFT_BLACK);

  // Draw 12 lines
  for (int i = 0; i < 360; i += 30) {
    sx = cos((i - 90) * 0.0174532925);
    sy = sin((i - 90) * 0.0174532925);
    x0 = sx * 38 + 40;
    yy0 = sy * 38 + 40;
    x1 = sx * 32 + 40;
    yy1 = sy * 32 + 40;

    M5.Lcd.drawLine(x0, yy0, x1, yy1, TFT_WHITE);
  }

  // Draw 60 dots
  for (int i = 0; i < 360; i += 6) {
    sx = cos((i - 90) * 0.0174532925);
    sy = sin((i - 90) * 0.0174532925);
    x0 = sx * 34 + 40;
    yy0 = sy * 34 + 40;
    // Draw minute markers
    M5.Lcd.drawPixel(x0, yy0, TFT_WHITE);

    // Draw main quadrant dots
    if (i == 0 || i == 180) M5.Lcd.fillCircle(x0, yy0, 2, TFT_WHITE);
    if (i == 90 || i == 270) M5.Lcd.fillCircle(x0, yy0, 2, TFT_WHITE);
  }

  M5.Lcd.fillCircle(40, 40, 2, TFT_WHITE);
  M5.Lcd.drawCentreString("WAyKEy", 120, 260, 4);

  targetTime = millis() + 1000;

  M5.Axp.ScreenBreath(9);
  M5.MPU6886.Init();

}
void brightnessT() {
  M5.MPU6886.getAccelData(&accX, &accY, &accZ);
  accX *= 1000;
  accY *= 1000;

  if ((accX > (200) && (accX < 900)) && ((accY > 0 - 300) && (accY < 300)))
  {
    if (millis() > (tiltTime + 500)) {
      M5.Axp.ScreenBreath(12);
      brightnessTime = millis();
      //    while (accX < (0 - 500) && ((accY > 0) && (accY < 100)));
    }
  }
  else
    tiltTime = millis();

  if (brightnessTime < millis() - 2000)
  {
    M5.Axp.ScreenBreath(7);
    brightnessTime = 0;
  }
}
void wristWatch() {
  if (targetTime < millis()) {
    targetTime += 1000;
    ss++;              // Advance second
    if (ss == 60) {
      ss = 0;
      mm++;            // Advance minute
      if (mm > 59) {
        mm = 0;
        hh++;          // Advance hour
        if (hh > 23) {
          hh = 0;
        }
      }
    }

    // Pre-compute hand degrees, x & y coords for a fast screen update
    sdeg = ss * 6;                // 0-59 -> 0-354
    mdeg = mm * 6 + sdeg * 0.01666667; // 0-59 -> 0-360 - includes seconds
    hdeg = hh * 30 + mdeg * 0.0833333; // 0-11 -> 0-360 - includes minutes and seconds
    hx = cos((hdeg - 90) * 0.0174532925);
    hy = sin((hdeg - 90) * 0.0174532925);
    mx = cos((mdeg - 90) * 0.0174532925);
    my = sin((mdeg - 90) * 0.0174532925);
    sx = cos((sdeg - 90) * 0.0174532925);
    sy = sin((sdeg - 90) * 0.0174532925);

    if (ss == 0 || initial) {
      initial = 0;
      // Erase hour and minute hand positions every minute
      M5.Lcd.drawLine(ohx, ohy, 40, 40, TFT_BLACK);
      ohx = hx * 15 + 40;
      ohy = hy * 15 + 40;
      M5.Lcd.drawLine(omx, omy, 40, 40, TFT_BLACK);
      omx = mx * 20 + 40;
      omy = my * 20 + 40;
    }

    // Redraw new hand positions, hour and minute hands not erased here to avoid flicker
    M5.Lcd.drawLine(osx, osy, 40, 40, TFT_BLACK);
    osx = sx * 25 + 40;
    osy = sy * 25 + 40;
    M5.Lcd.drawLine(osx, osy, 40, 40, TFT_RED);
    M5.Lcd.drawLine(ohx, ohy, 40, 40, TFT_WHITE);
    M5.Lcd.drawLine(omx, omy, 40, 40, TFT_WHITE);
    M5.Lcd.drawLine(osx, osy, 40, 40, TFT_RED);

    M5.Lcd.fillCircle(40, 40, 2, TFT_RED);
  }
  dd = RTC_DateStruct.WeekDay;
  weekDay();
  Date();
}

void weekDay() {
  M5.Lcd.setCursor(110, 12, 2);
  M5.Lcd.setTextColor(WHITE, TFT_GREY);

  //  M5.Lcd.print(dd);
  switch (dd) {
    case 1:
      M5.Lcd.print("SUN");
      break;
    case 2:
      M5.Lcd.print("MON");
      break;
    case 3:
      M5.Lcd.print("TUE");
      break;
    case 4:
      M5.Lcd.print("WED");
      break;
    case 5:
      M5.Lcd.print("THU");
      break;
    case 6:
      M5.Lcd.print("FRI");
      break;
    case 0:
      M5.Lcd.print("SAT");
      break;
  }
}

void Date() {
  M5.Lcd.setCursor(110, 26, 2);
  M5.Lcd.setTextColor(WHITE, TFT_GREY);
  M5.Lcd.print(DD);
  M5.Lcd.print('/');
  M5.Lcd.print(MM);
}

void batteryLevel() {
  M5.Lcd.setCursor(110, 3, 1);
  c = M5.Axp.GetVapsData() * 1.4 / 1000;
  b = M5.Axp.GetVbatData() * 1.1 / 1000;
  //  M5.Lcd.print(b);
  battery = ((b - 3.0) / 1.2) * 100;

  if (c >= 4.5) {
    M5.Lcd.setTextColor(TFT_YELLOW, TFT_GREY);
    M5.Lcd.print("CHG:");
  }
  else {
    M5.Lcd.setTextColor(TFT_GREEN, TFT_GREY);
    M5.Lcd.print("BAT:");
  }

  if (battery > 100)
    battery = 100;
  else if (battery < 100 && battery > 9)
    M5.Lcd.print(" ");
  else if (battery < 9)
    M5.Lcd.print("  ");
  if (battery < 10)
    M5.Axp.DeepSleep();

  //  if (digitalRead(M5_BUTTON_HOME) == LOW) {
  //    while (digitalRead(M5_BUTTON_HOME) == LOW);
  //    M5.Axp.DeepSleep(SLEEP_SEC(1));
  //  }
  M5.Lcd.print(battery);
  M5.Lcd.print("%");
}

void batterySaver() {
  M5.MPU6886.getAccelData(&accX, &accY, &accZ);
  accX *= 1000;
  accY *= 1000;

  if (!((accX > (200) && (accX < 900)) && ((accY > 0 - 300) && (accY < 300))))
  {
    if (millis() > (tiltTime2 + 3000)) {
  //    M5.Axp.DeepSleep();
      digitalWrite(33, LOW);
      M5.Axp.DeepSleep(SLEEP_SEC(20));
      //    while (accX < (0 - 500) && ((accY > 0) && (accY < 100)));
    }
  }
  else
    tiltTime2 = millis();
    digitalWrite(33, HIGH);
}

void loop() {

  brightnessT();


  wristWatch();


  batteryLevel();


  batterySaver();
}

static uint8_t conv2d(const char* p) {
  uint8_t v = 0;
  if ('0' <= *p && *p <= '9')
    v = *p - '0';
  return 10 * v + *++p - '0';
}

But there is an issue with the device and even when "powering off the "board" thanks to the AXP192 there is still 1.92 mAh consumed :'(

I put my Fluke current meter in series with the battery connection on my M5StickC.

With screen on it draws approximately 80ma
When I call M5.Axp.DeepSleep(); 15ma.

There's something very wrong going on here....

#include <M5Stack.h>

#define uS_TO_S_FACTOR 1000000 /* Conversion factor for micro seconds to seconds /
#define TIME_TO_SLEEP 3 / Time ESP32 will go to sleep (in seconds) */

RTC_DATA_ATTR int bootCount = 0;

void setup()
{
M5.begin();

delay(500);

if (bootCount == 0) //Run this only the first time
{
	M5.Lcd.printf("first time");
}
else
{
	M5.Lcd.println(String(bootCount));
}

bootCount = bootCount + 1;
delay(3000);

M5.Lcd.clear();

esp_sleep_enable_timer_wakeup(TIME_TO_SLEEP * uS_TO_S_FACTOR);
esp_deep_sleep_start();

}

void loop()
{

}

From the data sheet, the chip itself draws 10uA in deep sleep. Integrator's boards draw between 12uA to 10mA. The m5stack isn't very power efficient and with the the "leaking" speaker amp it may be in the high teens. I'll measure mine when I get home on Monday.

In the meantime you can start with this tuto on deep sleep mode. The mention of a limitation, or could be a bug of the esp32, it needs to wait 500ms after wakeup or it randomly won't wake up again.