So you're a Noob? Post your questions here until you graduate! Don't be shy.

User avatar
By carthapango
#94652 Hi! I have an ESP8266 NodeMCU dev board and five reed switches. I would like to be able to detect when each of them may be disconnected (got a normally open one, default position is magnet next to reed switch.)

From what I can gather online, it looks like people like to use external resistors to connect the reed switch to their board, but I also read that several GPIOs on this board has internal pullup resistors.

My questions are:
- which GPIO pins should I use as INPUT_PULLUP for the five reed switches;
- how should I wire them up -- if I need an external resistor per switch, how much should I use?
- lastly, has anyone tried something like this but using ESPHome with Homeassistant?

Thank you so much and sorry for my noob question!