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Re: PIR sensor - wake and sleep using CH_PD & thingspeak upd

PostPosted: Tue Feb 21, 2017 1:51 pm
by Barnabybear
Hi, I used some old stock I had kicking about in the workshop KC7783R's which is a 5 to 12V PIR, I used a 1K /2K resistor divider on the output line to give 3.3V.

http://www.electronics123.net/amazon/da ... c7783r.pdf

EDIT: Another thought. Which ESP module or development board ae you using? Some have a 10K pull up on CH_PD, that could change things, I used an ESP8266-01.

Re: PIR sensor - wake and sleep using CH_PD & thingspeak upd

PostPosted: Tue Feb 21, 2017 10:15 pm
by jhumphr
Barnabybear wrote:Hi, I used some old stock I had kicking about in the workshop KC7783R's which is a 5 to 12V PIR, I used a 1K /2K resistor divider on the output line to give 3.3V.

http://www.electronics123.net/amazon/da ... c7783r.pdf

EDIT: Another thought. Which ESP module or development board ae you using? Some have a 10K pull up on CH_PD, that could change things, I used an ESP8266-01.


Your PIR is different, but I'm not seeing anything that would cause this. Hmm... And yeah I'm using the ESP-01 as well

Re: PIR sensor - wake and sleep using CH_PD & thingspeak upd

PostPosted: Wed Feb 22, 2017 5:30 pm
by jhumphr
I think it's the PIR. The chip can't put out enough current from the looks of my multimeter measurements. How did you power that PIR with 3.3v like in the diagram? Bypass the regulator? Or did you use a 5v power supply?

Re: PIR sensor - wake and sleep using CH_PD & thingspeak upd

PostPosted: Thu Feb 23, 2017 6:13 pm
by Barnabybear
Hi, mine was 5V and powered from 5V with a 1k / 2*1k voltage divider on the output. If your powering this:
https://www.mpja.com/download/31227sc.pdf
from 3.3V your not going to get a good output.

Looking at the above data sheet and this one:
https://cdn-learn.adafruit.com/assets/a ... SS0001.pdf

It looks like you can bypass the voltage regulator by feeding 3.3V to the:
'H: Repeat Trigger' pin on the board. This can be the same supply as the ESP as long as it can supply 300mA (ESP) plus the 65mA the PIR needs.