PIR am312

[NeverDie]

I ran a banggood PIR sensor off my 3.3v boosted 10F supercap solar node last night and, as you would expect, the extra load was so low that it's practically a rounding error. :) These PIR's would have no problem being powered for days from a supercap.

@Nca78 I guess what you're calling "sensibility" on your board above is another name for sensitivity? i.e. you figured out how to adjust the sensitivity of the PIR detector? That's something not obviously accessible on the banggood PIR's, as they don't seem to come with a sensitivity adjustment. If you've already figured out how to adjust the sensitivity, would you mind sharing the schematic? It might help us avoid re-inventing the wheel if we were to follow the path you've already blazed.

[Nca78]

@NeverDie haha yes it's the sensitivity sorry sometimes my English fails and I mix with French words :D
I will fix on the PCB.

This can be set only on am612, I bought the sensor only (no breakout board) on AliExpress. It has 6 pins for the extra settings instead of the 3 of the am312.

[NeverDie]

@Nca78 said in PIR am312:

@NeverDie haha yes it's the sensitivity sorry sometimes my English fails and I mix with French words :D
I will fix on the PCB.

This can be set only on am612, I bought the sensor only (no breakout board) on AliExpress. It has 6 pins for the extra settings instead of the 3 of the am312.

Good to know. Does it draw the same or comparable amount of current as the am312? If so, you've just saved me from ordering the wrong sensor! :)

[Nca78]

@NeverDie said in PIR am312:

Good to know. Does it draw the same or comparable amount of current as the am312? If so, you've just saved me from ordering the wrong sensor! :)

The datasheets are similar for everything that is not related to the extra pins of course: same electrical specs, same detection profile, ... My guess is it's the same PIR sensor but on am312 some of the settings are just hardwired inside the "can".

[NeverDie]

Cool! I'm going to follow your lead and order some of the am612's then. Thanks for the heads up!

[scalz]

sensitivity can be adapted in sw

[Nca78]

@scalz said in PIR am312:

sensitivity can be adapted in sw

For am312 ? How would you do that when all you have are Vcc, GND and signal pin ?

[NeverDie]

I ordered these:
https://www.aliexpress.com/item/10pcs-AM612-DIP6-human-infrared-sensor-module-pyroelectric-infrared-sensors-Sensor/32604041429.html?spm=2114.01010208.3.15.vPmcAS&ws_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10130_10068_5010014_10136_10157_10137_10060_10138_10155_10062_10156_437_10154_10056_10055_10054_10059_303_100031_10099_10103_10102_10096_5170015_10147_10052_10053_10107_10050_10142_10051_5190015_10084_10083_10119_10080_10082_10081_10178_10110_519_10111_10112_10113_10114_10037_10183_10182_10185_10033_10032_10078_10079_10077_10073_10123_10120_142,searchweb201603_4,ppcSwitch_4&btsid=99796fa2-b6d9-451b-89ee-c690f3ec0542&algo_expid=357f8654-d7b8-423c-8af7-8a8a924a49a5-2&algo_pvid=357f8654-d7b8-423c-8af7-8a8a924a49a5

[NeverDie]

Not sure if this is the same as the SR501 lens. Really hard to tell from the photo:
https://www.aliexpress.com/item-img/5Pcs-Lot-PIR-human-body-infrared-sensor-lens-Mini-lens-high-quality/32563535500.html?spm=2114.10010108.1000017.1.oavh25
If anyone finds a confirmed source for SR501 lenses, please post.

[Nca78]

SR501 lens is referenced as 8002-2. But it seems all those big fresnel lenses with 4 pins are the same, I suppose one original maker and a bunch of copycats.

[scalz]

@Nca78 said in PIR am312:

@scalz said in PIR am312:

sensitivity can be adapted in sw

For am312 ? How would you do that when all you have are Vcc, GND and signal pin ?

with timers. but, it's a bit more power hungry if using simple 8bits mcu, not a problem with more powerful mcus like ARM etc. which have more low power features.

[Nca78]

@scalz said in PIR am312:

with timers. but, it's a bit more power hungry if using simple 8bits mcu, not a problem with more powerful mcus like ARM etc. which have more low power features.

Still not getting it :)
This sounds more like a solution to manage "on" time when triggered but I don't get how this could make your sensor detect at 5m instead of 3m ?

[scalz]

@Nca78
oki. lol i messed a bit with terms too :blush: yes for "on" time.
for 5m instead of 3m, this will depends of sensor quality and its lens. I think in datasheet they give a max range for an ideal lens, or that wouldn't make sense to get long range with a crappy lens..

[NeverDie]

@scalz said in PIR am312:

@Nca78
oki. lol i messed a bit with terms too :blush: yes for "on" time.
for 5m instead of 3m, this will depends of sensor quality and its lens. I think in datasheet they give a max range for an ideal lens, or that wouldn't make sense to get long range with a crappy lens..

So, Scalz, are you saying that out of the box, the am312 is hard-wired for max sensitivity, and then to get lower sensitivity, you add impairments, such as a lower duty cycle (less "ON" time) and/or a crappier lens? Wow, is that how this stuff is actually meant to work? I was hoping that maybe the am612 could be optionally tweaked for more sensitivity than the am312. If I'm understanding you (and if you're right), though, then I guess that won't be possible. I had assumed (perhaps wrongly) that the am312 defaulted to a "medium" amount of sensitivity, not a maximum amount of sensitivity. Do you happen to know whether am312 defaults to maximum sensitivity or not?

[NeverDie]

Anyhow, looking at the reference circuit design in the am612 "sensor manual" (see page 7 of http://akizukidenshi.com/download/ds/senba/Pir-Am612.pdf), I see that there is a photoresistor (a GL5528) there. Is it somehow adjusting the sensitivity based on the ambient light level? The GL5528 appears to be sensitive to 540nm light (i.e. green light) according to its datasheet
(http://akizukidenshi.com/download/ds/senba/GL55 Series Photoresistor.pdf). I'm not sure that's a trick that the am312 can do. Can it?

I just love these Ford vs. Chevy debates. :)

By the way, where should that photoresistor be positioned? Under the IR lens, or should it have its own window? I'm guessing under the IR lens to keep things "tidy".

[Nca78]

@NeverDie said in PIR am312:

I just love these Ford vs. Chevy debates. :)

We are French, we only have Peugeot vs Citroën debates, or Renault vs Peugeot :D

Else @scalz misunderstood what we were talking about, he was just talking about changing the "on" duration of the sensor by software (as it's fixed on the am312). No the sensitivity.

About the photoresistor in the doc is connected to the OEN pin (Output ENable) of the AM612 (one more pin the am312 doesn't have), so that with the reference design it will only trigger and switch on the light when it's dark.

[sundberg84]

I recieved mine today and changed a HC-SR501 on a working Slim node to this but I failed to make it work.
I then tried to remove the voltage regulator (red arrow) and solder the jumper (blue) to power it from the bat but even with fresh batterys... no go! I watched the circuit to make sure i found VCC/GND and out but maybe i understood something wrong.

The second i put the old HC pir back that one worked again.
Any ideas?

[NeverDie]

@sundberg84

Any chance you hooked up the polarity wrong when you tried it out? I did that to one of my three and completely fried it. It's dead.

Your PCB looks the same as mine, but the silkscreen is different. The polarity you marked on your photo looks correct to me, and it agrees with the "+" sign on your silkscreen. Mine didn't come with a "+" on the silkscreen.

Unrelated to your question, but I notice that yours came with a different lens. Do you have a link to where you bought yours?

[sundberg84]

@NeverDie http://www.ebay.com/itm/262527326905?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I had two and tested them, maybe I fried them... but i dont think so.

[NeverDie]

@sundberg84

Check to see how much current it's drawing when you have it powered up. If it's fried, it will be drawing more than expected.

Also, try connecting a voltmeter between the middle pin and ground with it powered on. When it detects motion, you'll notice a change in voltage.