ESP8266 Community Forum

- Wed Mar 11, 2020 7:32 am #86023 am using a D1 Mini V2 (ESP-12) as the basis for an indoor temperature sensor. I only need readings every 10 minutes so I am implementing deep sleep. My understanding is that to wake up out of sleep, D0 and RST pins on the D1 Mini should be connected together. I have done this using a 330ohm resistor. However, the D1 Mini is not coming out of sleep successfully - it wakes but the script doesn't run.

After some experimentation on the breadboard I have found that it will come out of sleep successfully if, after the time has elapsed, I momentarily short RST to ground with a wire (it wakes up after the short is removed).

Is there something around the configuration of pin D0 that means it is not providing an appropriate momentary low signal to RST at the end of sleep? Do I need to do something different either in hardware or software?

- Thu Mar 12, 2020 5:35 am #86036 There is a capacitor on the reset line which makes it trickier to use a resistor in line with it.

It is best to use a diode (schottky for preference) with the anode to reset line and cathode to GPIO16 (D0). That will then a low impedance path to pulse the reset line.

Note that the extra circuitry on a D1 (usb serial) will draw current even with the module in deep sleep. This will lower the battery operational time. If you want the best deep sleep then you should deploy with something like a ESP-12F