# NodeMCU v.1 / WEMOS Mini - Fail to Wake up from deep sleep

I'm Trying to put to deepsleep a Wemos mini/ NodeMCU / ESP-01, and facing the same problem - fail to wake up.

Looking around - I've found some articles such this github issue, and this issuedescribing same behavior of not waking up as expected.

code as posted in first github issue, which is very simple:

void setup() {
Serial.begin(74880);
Serial.setTimeout(2000);
while (!Serial) { }
Serial.println("Started.");
delay(5000);
Serial.println("Going to sleep.");
ESP.deepSleep(30e6);
}

void loop() { }


Hardware setup: pins connected: RST + D0

But at the end - I found no solution but saying that "some of chips/ boards fail to wake up".

Since all my boards at hand fail, I don't know if is if the formal answer for that phenomena.

Any assistance will be appreciated,

• esp-01 doesn't have io 16 accessible, so you can't wake it up from deep sleep. esp8266 pin io 16 (D0 on NodeMcu and WemodD1 mini) is connected to inernal RTC of the esp8266, which doesn't sleep and counts down the sleep time. to wake up the esp the RTC connects io 16 to ground. if the reset pin has an external pull-up resistor with low resistance, the io 16 can't pull it down to reset. – Juraj Dec 17 '19 at 10:28
• @Juraj thank you for your comment. First, I don't use ESP-01, but Wemos and NodeMCU, which GPIO16 is not accessible. Second, since boards used in tutorials ( same models as I did try ), can accomplish waking up, I try to understand who or what is wrong my with boards, and how can I check it/ fix/ buy others ? – Guy . D Dec 17 '19 at 17:50