ESP Home with wmos mini boot probleme

ESPHome
1

Hello,
I am using a wmos d1 mini with esp home to control water valves in our garden. That works perfectly fine. Since last week I added a rain sensor with a potential free contact. It just is closed if the sensor is dry and it opens when it rains.
Here the ESP Home Code

binary_sensor:
  - platform: gpio
    pin:
      number: GPIO2
      mode:
        input: true
        pullup: true
    name: Rain
    device_class: moisture

Now the Problem I got. When the rain-sensor is connected to ground and D4 (with pullup) the wmos mini will not startup properly - its will never show up in Home Assistant. After disconnecting the rain sensor, the wmos mini comes up as normal. I also can connect the rain sensor afterwards an everything including the rain sensor works fine. The question: What happens during the startup, the prevents the normal boot if ground and D4 is connected?
Thanks for your help.

2

GPIO2 (D4) is connected to an integrated LED, startup will fail if pulled LOW.
Use a different pin.

1 Like
3

Have a look at ESP8266 Pinout Reference: Which GPIO pins should you use? | Random Nerd Tutorials to see which pins are safe to use.

2 Likes