any idea how to do this with the M5Paper?

cheers

just added a redraw of the screen and it all works:

  // turn on power to screen
  M5.enableEPDPower();
  // redraw screen
  canvas.pushCanvas(0, 0, UPDATE_MODE_DU4);
  // turn on power to ports
  M5.enableEXTPower();

the screen does get a bit of greyish line pattern over time:

please find an explanation here. (It's for M5CoreInk, but I think the same thing is happening here.)

Thanks
Felix

M5.disableEXTPower()

hi felix,

turning off external power works. great!

about turning back on the screen, please see code and screen pictures below. without M5.disableEPDPower() and M5.enableEPDPower() it all works nicely. with turning on/off the screen i do see sort of that it is running but the screen does not "work" properly - i.e. i do not see the number increasing. (and "the noise" is getting worse over time). what am i doing wrong?

thanks
frank

#include <M5EPD.h>
#include <EEPROM.h>

// m5paper
M5EPD_Canvas canvas(&M5.EPD);


int count;
int boot;

void setup() {
  
  M5.begin();

  M5.EPD.SetRotation(0);

  // cleanig the screen by alternating all pixels set, all pixels reset
  M5.EPD.Clear(true);

  // use rtc
  M5.RTC.begin();

  canvas.createCanvas(960, 540);
  canvas.setTextSize(8);

  canvas.clear();
  canvas.drawString("Sleep Test...", 50, 50);
  canvas.pushCanvas(0, 0, UPDATE_MODE_DU4);

  delay(1000);

  EEPROM.begin(10);
  boot = EEPROM.read(0);
  boot++;
  EEPROM.write(0,boot);
  EEPROM.commit();

  count = 0;
}

void loop() {

  canvas.clear();
  char printBuffer[64];
  sprintf(printBuffer, "b=%d, c=%d",boot, count);
  canvas.drawString(printBuffer, 50, 50);
  canvas.pushCanvas(0, 0, UPDATE_MODE_DU4);

  count++;

  delay(1000);

  gpio_hold_en((gpio_num_t)M5EPD_MAIN_PWR_PIN);
  esp_sleep_enable_timer_wakeup(5 * 1000000);
  
  // turn off power to screen
  // M5.disableEPDPower();
  // turn off power to ports
  M5.disableEXTPower();

  // sleeps, wakesup and continues
  esp_light_sleep_start(); 

  // sleeps, wakesup and restarts
  // esp_deep_sleep_start();

  // shutsdown
  // M5.shutdown(5);

  // turn on power to screen
  // M5.enableEPDPower();
  // turn on power to ports
  M5.disableEXTPower();
}

without turning off/on power to screen:

with turning off/on power to screen:

Re enable power to the screen: what do you mean M5.enableEPDPower() isn't enough?

Re Groove ports: you can only turn off all three ports together. Try M5.disableEXTPower().

BTW: Only fully powering down M5Paper will give you lowest power. At the time I did some measurements. You can find them here.

Thanks
Felix