Can't get deep sleep to work on Wemos D1 ESP8266

Question

I have a Wemos D1 (ver. 2015-08) and I am trying to get it to sleep. I've managed to get it generally up and running/got wifi to work etc, but the deep sleep function is beyond me.

I tried connecting RX<-D0 pin to RESET, also tried with a 10k resistor. Neither worked. I then tried D2 (listed as gpi016 on the back of the board) to RESET, this also didn't work. Any ideas? It seems like this would be an incredible chip if I could get it to sleep. The example sketch below uploads fine and contacts the serial monitor, up until the point it sleeps.

 /* Deep Sleep - Blink
 *
 * Blinks the onboard LED, sleeps for 10 seconds and repeats
 *
 * Connections:
 * D0 -- RST
 *
 * If you cant reprogram as the ESP is sleeping, disconnect D0 - RST and try again
 */

// sleep for this many seconds
const int sleepSeconds = 5;

void setup() {
  Serial.begin(9600);
  Serial.println("\n\nWake up");
  pinMode(BUILTIN_LED, OUTPUT);
  // Connect D0 to RST to wake up
  pinMode(D0, WAKEUP_PULLUP);
  // LED: LOW = on, HIGH = off
  Serial.println("Start blinking");
  for (int i = 0; i < 20; i++) {
    digitalWrite(BUILTIN_LED, LOW);
    delay(100);
    digitalWrite(BUILTIN_LED, HIGH);
    delay(100);
  }
  Serial.println("Stop blinking");
  Serial.printf("Sleep for %d seconds\n\n", sleepSeconds);
  // convert to microseconds
  ESP.deepSleep(sleepSeconds * 1000000);
  Serial.println("sleep finished");
}

void loop() {
}

Answer 1

I had to physically connect D0 to RST to wake up the wemos.

Answer 2

In fact it works well using a wire between D2 and RESET pins. But sending the program to the board, you must first disconnect these pin (the arduino IDE will send a hard reset during process, so this D2 reset must not be in place). When the program is uploaded to the ESP and start running, you connect D2 and RESET and it works well, ESP will go to deep sleep mode as expected.

Because it is not a mini, the board has another chip (usb) that will not got to sleep mode, so on my board it will use about 17mA in deep sleep (compare with 80mA in wifi normal operation). Still worth the trick.