nodemcu and ESP EASY

[wifi75]

Hello to all,
I have home alarm and when it is armed on two pins there are + 12v.
I have already programmed a nodemcu esp8266 module withc espeasy rev12 and connecting to gpio 0 one relay.
I would like to know how is possible connect the +12v to my esp8266 and when I armed this closes relay contact connected to gpio 0.

It is possible ? How?

[wifi75]

no idea?

[grovkillen]

You need to get the 12V down to 3.3V and have that connected to a GPIO acting as a switch (3.3V=HIGH=1, 0V=LOW=0) and have that trigger an output to an relay connected to another GPIO. But you could also do this without the use of a ESP if you want. Have the alarms output trigger an relay, no need for the microcontroller (even though it might be nice to monitor this anyway). To lower the voltage you need to divide it:

https://www.letscontrolit.com/wiki/inde ... ge_divider

https://learn.sparkfun.com/tutorials/voltage-dividers

[papperone]

I am not in favour to connect anythign as a input directly to a GPIO; I woudl rather use a optocoupler to prevent any issue/damage to the ESP itself

by the way I agree with @grovkillen why you need NodeMCU and ESPEasy if you can close a 12V relay directly from the 12VDC output signal ??

[grovkillen]

I am not in favour to connect anythign as a input directly to a GPIO

Yes, don't listen to me... I'm just the wiki guy and know little to nothing about the electronics of things

[wifi75]

I want trasforming my hone security to wifi.
And with domoticz I can use this.