ESP8266 Community Forum

- Mon Dec 14, 2015 5:38 pm #36433 Hi, if your PIR will run at 3.3V and your nodemcu looks like the one in the link below,
https://github.com/nodemcu/nodemcu-devkit
You should be able to take the power from the 3.3V and GND next to the flash button and use the values as shown in the post.
If your PIR is 5V you will need to make a voltage divider from 3 1K resistors or ( 1k & a 2.2K).

Output from PIR -> 1K resistor -> Input to ESP circuit -> 1K resistor -> 1K resistor -> Ground.
See this post. http://jamesreubenknowles.com/level-shi ... ments-1741
Strategy #4 & don't worry about the Danger note at the end - this was taken into account when using 1K.

- Fri Dec 18, 2015 5:10 pm #36747 Ah, so sorry. I kept refreshing on the previous page from my mobile and didn't see your answer.

Actually I am using push button, therefore no hassle with voltage dividing the PIR

Kind of obvious to use the 3.3V output of the board, but I did not think of it!

Is it really necessary to keep the reset-pin high?
On this website the author is also using a capacitor https://blog.the-jedi.co.uk/2015/11/08/internet-button/

Thank you for your fast help!

- Fri Dec 18, 2015 7:59 pm #36754 Hi, you could use a capacitor, the problem is that once the capacitor discharges the ESP will shut down regardless of whether the task has been completed or not.

- Sun Dec 27, 2015 6:38 am #37219 Hey all,

I was wondering if you could not use a 555 timer between the sensor and the esp to control the length of the signal. The 555 does require a low input trigger but a nor gate might solve that.

Just an idea. The standard timers do work on 5v but I saw some that run on batteries.

Regards rens