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

PostPosted: Thu Aug 20, 2015 11:37 am
by noelportugal
Yes @tytower, sorry for the brevity. I just wanted to give some sort of recognition to @Barnabybear.
In his first post here he gave me the idea to wake up and sleep using CH_PD.

Barnabybear wrote:The PIR could be replaced with a reed switch for doors or a button for checking that a location had been visited.


So I'm using a button instead of the PIR. So far battery life with 2 Alkaline AA is great. I also removed the red LED for good measure.

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

PostPosted: Thu Aug 20, 2015 12:32 pm
by reddatto
Oops.

Sorry again guys. That's what I get for posting stuff at 3am.

I get the diode. If the PIR can sink current it will cause the +vcc from the input pin to flow from the high impedance input pin to the low impedance output pin on the sensor.

No need to post either of these unless it will help someone...

LOL, Garth.

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

PostPosted: Thu Aug 20, 2015 3:47 pm
by kolalde
Fwiw, excellent thread.

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

PostPosted: Mon Aug 24, 2015 3:36 pm
by DaniloFix
Very interesting thread. I'm actually looking to build something similar. I want to use a vibration sensor like the SW-18020P to power up the ESP but that won't last 325 ms that seems to be required. See a demonstration of the sensor here: http://www.electroons.com/blog/2013/08/ ... h-testing/

I read a few places that the SW18020P conductive / contact time was 2 ms, so pretty far from the needed 325 ms. So the million dollar question is, how to keep the pin high, long enough to wake up the ESP from power off state?

Perhaps one or more small capacitors in parallel could do the trick? That is, if they can charge fast enough