💬 AM612 Passive Infrared Sensor Breakout Board

[openhardware.io]

https://www.openhardware.io/view/420/AM612-Passive-Infrared-Sensor-Breakout-Board

[NeverDie]

It works. Project completed.

[sundberg84]

Are you happy with this sensor? I mean, compared to HC-SR501 this must be a breeze to use on a PCB (size and 3 resistors only?)?
How do you grade it in motion detection compared to HC-SR501? Is this a sensor you recommend if you want to build a motion dec PCB?

[NeverDie]

@sundberg84 said in AM612 Passive Infrared Sensor Breakout Board:

Are you happy with this sensor? I mean, compared to HC-SR501 this must be a breeze to use on a PCB (size and 3 resistors only?)?
How do you grade it in motion detection compared to HC-SR501? Is this a sensor you recommend if you want to build a motion dec PCB?

Answers: yes, yes, don't know, yes

[NeverDie]

I updated the module to be plug compatible with the Multi-Sensor:
https://www.openhardware.io/view/510/Multi-Sensor-TempHumidityPIR-LeakMagnetLightAccel

[NeverDie]

Updated files to version 503 so that the PIR is better centered above the multi-sensor.

[Omemanti]

Looks awesome, do you by chance have the schematic as a PDF?

[NeverDie]

@omemanti said in AM612 Passive Infrared Sensor Breakout Board:

Looks awesome, do you by chance have the schematic as a PDF?

OK, I just now uploaded the PDF schematic for version 506, which is a newer (more simplified) version than the actual gerber files. I'll update the gerber's later. Version 506 is the most current version.

[Omemanti]

@neverdie Thankyou!

[NeverDie]

i uploaded all the files now for version 506, which is the most current version. Version 506 requires fewer components than earlier designs.

[BC547]

The link to the PIR lens does not seem to work anymore (404 not found error).
Did you try e.g. https://www.aliexpress.com/item/10PCS-Infrared-Sensor-8308-4-mini-White-Fresnel-Lens-body-pyroelectric-PIR/32780943866.html ? This lens seems even smaller. Or are there disadvantages to being too small?

[NeverDie]

@bc547 said in AM612 Passive Infrared Sensor Breakout Board:

Or are there disadvantages to being too small?

Optics aren't as good. Also, unless the radio and power source are equally small, you don't get the advantage of the smaller size.

[waspie]

does anyone have a sample sketch for this. i don't understand the whole pin assignment thing well enough to know what the heck i'm doing.

I grabbed the sketch from the 10 year pir but this seems much more geared to the nrf52

[mfalkvidd]

@waspie just use the same sketch and wiring as in https://www.mysensors.org/build/motion except that AM612 wants 3.3V instead of 5V.

[waspie]

@mfalkvidd
yeah, I don't think that's working. I think I may understand better why not, so correct me if I'm wrong.

The low power comparator only works on analog inputs and in the nrf51 board by @NeverDie the SCL marked pin on the board is tied to P0.10 which has no analog input on it.

So, what I think I need to do is cut the trace and re-route it to the INT marked on the board which is tied to P0.03 which is analog 1 (AIN1). At that point then I think I only need to change the line in the sketch to use pin 3 instead of 2.

[mfalkvidd]

@waspie sorry. I didn't realize you're using NRF5. I thought you wanted to connect it to a "regular" Arduino like Nano or Pro Mini.

I don't have any experience with NRF5 unfortunately, but hopefully someone else can help.

[Omemanti]

@waspie you might want to look at one of my projects on openhardware. It has a sketch on it. It also uses the am612

[waspie]

Thanks.
I'm really not too good at writing arduino code but I did come across this library:
https://github.com/mristau/Arduino_nRF5x_lowPower

Is this something that could be incorporated into the sketch and then use "normal" interrupts?

[nagelc]

Don't cut your trace just yet. You can use normal interrupts with MySensors and NRF5, at least if you are sleeping the node. I have used the normal Mysensors sleep statement, with interrupts for buttons, and not had to use the LPCOMP. The motion sensor should work similarly. I have used interrupts on P0.27 for a button interupt, which is regular GPIO pin and not an analog pin. I have also used 2 interrupts in the sleep statement, which means the MySensors NRF5 code probably uses GPIOTE instead of LPCOMP for interrupts. Might not be as low power as LPCOMP, but it seems to be more flexible.
I used an NRF52832, haven't tried with a NRF51 board.

[Omemanti]

@nagelc I also use normal interrupts. No problems here. Up to 22uA while sleeping, that's fine by me. (3 AAA will last a long time)

[waspie]

yeah well i got a few nrf51822 which was evidently a big mistake

[Omemanti]

@waspie why?

[waspie]

They don't seem to play well and seems like most or any of you guys messing with NRF5x are preferring nrf52.

I have however figured out one problem. Whenever my nrf51 was sleeping i was seeing 1ma current which is a deal killer. I accidentally discovered that disconnecting the st link and replugging it got sleep current to ~5ua. Something about uploading the program puts it in some state whereby it won't sleep properly.

So, I can get it to sleep all the way down now and I'm starting to understand the psel refsel stuff. And, I can make it trigger on p0.03 (an4 or 5, whatever) but its not particularly reliable. I need to get this section right:

void activateLpComp() {
  NRF_LPCOMP->PSEL=4; // monitor AIN0 (i.e. pin P0.02 on nRF52832 PIR Motion Sensor v607).
  while (!(NRF_LPCOMP->PSEL==4)) {} //wait until confirmed
  NRF_LPCOMP->REFSEL=2;  // choose 1/2 VDD as the reference voltage
  while (!(NRF_LPCOMP->REFSEL==2)) {} //wait until confirmed
  NRF_LPCOMP->ANADETECT=0;  //detect CROSS events on PIR detection pin
  while (NRF_LPCOMP->ANADETECT!=0) {} //wait until confirmed
  NRF_LPCOMP->INTENSET=B1000;  //Enable interrupt for CROSS event
  while (!(((NRF_LPCOMP->INTENSET)&B1000)==B1000)) {} //wait until confirmed
  NRF_LPCOMP->ENABLE=1;  //Enable LPCOMP
  while (!(NRF_LPCOMP->ENABLE==1)) {} //wait until confirmed
  NRF_LPCOMP->TASKS_START=1;  //start the LPCOMP
  while (!(NRF_LPCOMP->EVENTS_READY)) {}  //wait until ready
  
  NVIC_SetPriority(LPCOMP_IRQn, 15);
  NVIC_ClearPendingIRQ(LPCOMP_IRQn);
  NVIC_EnableIRQ(LPCOMP_IRQn);
}```

[waspie]

It's looking more and more like the code is fine and its the sensors i'm using that are the problem.

I got some BM612 (cheaper) from ali supposedly the same as am612 but they don't seem to work right. It's like they trigger once and then never again. Can't find a data sheet for them...

I hooked up a 312 just for kicks and it seems to be working. I doubt I'll deploy any 312s due to what seems to be a VERY narrow range and plus it doesn't match the profile of the round board etc...

Anyway, wanted to say that i think this is all working as its supposed to I just got a bad batch of sensors or they're slightly different in some way

[waspie]

For anyone looking to use @NeverDie 's nrf51 circular board (v9) with this breakout - I'm using the sketch as linked from @Nca78 in this post: https://forum.mysensors.org/topic/6961/nrf5-action/1542
in conjunction with the edit to the file as described in this post:
https://forum.mysensors.org/topic/6961/nrf5-action/1514 (the edit to WInterrupt.c and I'm using version 0.6.0 from sandeep)

with just a few minor edits to the sketch from Nca (setting the pin to 10 (sda marked on the circular board).

14ua idle current btw, working like a charm. so far i'm just using a 2032. Trying to figure out a way to strap a cr2450 or 2477 on the back

[nithino]

@waspie Apologies for resurrecting this thread after two years. I have quite a few NRF51822 boards with me. I would like to put it to use. Can you please share your code as following these links did not help me compile the sketch. Too many errors. Thanks in advance.

[gulsimsur]

I grabbed the sketch from the 10 year pir but this seems much more geared to the nrf52

[gulsimsur]

@gulsimsur said in AM612 Passive Infrared Sensor Breakout Board:

I grabbed the sketch from the 10 year pir but this seems much more geared to the nrf52
i don't understand the whole pin assignment thing well enough to know what the heck i'm doing.

[ejlane]

@gulsimsur Why are there links to surveyzop in your reply?

[MasterCATZ]

Thanks for the breakout board, but would it be too much to ask for a revision that can have potentiometers mounted?
so resistors do not need to be changed when tinkering with 15x settings? either SMD or Through-Hole Trimmer

0-300k None?,0-1M

[MasterCATZ]

Or a 12x DIP switch and a Jumper

Jumper for the shortest and longest Time settings
Then pads for installing the 12 Resistors for Time in Seconds the LED / Relay etc is activated for ?

also, how were you mounting these boards with no screw holes? just something for the lens cover to clip into

[NeverDie]

@MasterCATZ That's a reasonable request. In the future whenever I post a board to openhardware.io, I'll endeavor to include the complete set of KiCAD 6 files needed to make simple changes like this, so then I'm not the bottleneck. However, I did this work, and most of my other work to date, in Diptrace, which AFAIK doesn't allow that kind of easy change by other people.

Meanwhile, if anyone wants to re-do the board and post it with the asked-for change, feel free. Because I don't have that need myself, I won't be doing it, because it involves also spending time finding files in some forgotten archive from 5 years ago in order to resurrect it even before making the change.

In any case, I'm glad that at least some people have found it useful, which is why I posted it in the first place.

[MasterCATZ]

all good at least I can steal your sensor hole placements and can stumble along modding in KiCAD

tho unsure why the board size is smaller when I converted it it seems to trim along where the cover's holes are and not leaving any meat behind

did you come across any other sensors better than this for the price?

[MasterCATZ]

@waspie

https://robu.in/wp-content/uploads/2020/09/Pir-BM612.pdf

planning on switching over to these as well

sensitivity setting and better times

[NeverDie]

@MasterCATZ said in AM612 Passive Infrared Sensor Breakout Board:

did you come across any other sensors better than this for the price?

I vaguely recollect having since come across a newer aliexpress sensor with an even lower power consumption, but I can't say for sure. If that matters to you, it may be worth checking. It wouldn't surprise me, as there is constant progress, and 5 years is a long time.

[NeverDie]

@MasterCATZ and anyone else: If you come across a comparable PIR sensor at a comparable price but with a meaningfully lower current drain, please do post an update to this thread letting us know what it is. I do recollect there being at least one, but by now there may be even more. I could possibly create a new breakout board for it. As I just recently discovered, for a small board of this size, you can order 30 custom PCBs for under ~$5. The first five PCB's would cost $4, but after that the marginal cost is just pennies each. AFAIK, that kind of discounted pricing for hobbyists didn't exist 5 years ago. Either it's the new normal or else it's a temporary thing because of the pandemic or a grab for market share. Not sure which.

[ejlane]

@NeverDie Seems that JLCPCB has had great pricing for at least the past 3-4 years or so. It's been very consistently low every time I've gone looking. I think that's about as long as I've known about them.

[NeverDie]

A quick, cursory look at digikey, and I see that $5 (quantity: 1) will buy you a pir sensor that consumes only 3ua of current at 1.8v while in passive detection mode: https://www.digikey.com/en/products/detail/excelitas-technologies/PYD-1598-7655/6615456
That seems like pretty good performance to me, especially in such a tiny package. In contrast, the AM612 is 14ua at a cost of around $0.85 each (quantity 10 pricing).

Panasonic PIRs that operate at 2ua are available, but at around $20.

Sparkfun claims their PIR board (with a panasonic sensor in it) draws just 1ua, but their price for it is $33.50: https://www.sparkfun.com/products/17375

So, if price is no obstacle, there's a lot to choose from. However, here's how I look at it: use 2x lithium AA primary batteries to power your project (https://data.energizer.com/pdfs/l91.pdf). That's about 3500mah. Then, ignoring other power drains like wireless communications and self discharge, then with the AM612 (at 14ua current drain), those batteries should last you more than 28 years, which is longer than the 20-year shelf life of the batteries. So, unless I've made a calculation error, 14ua seems good enough to me. I guess the argument for the lower drain PIRs might make sense if you're doing energy harvesting.

[waspie]

for what its worth IIRC i'm getting at least 6 months on the ol' 612 with a CR2450.
Close to two years on a CR123a. So yeah, if I made more I'd design a new board for the new PIR sensors you're finding out there but the 612 even with its higher dropout voltage seems to work fine with even a moderatly sized battery.

[NeverDie]

@waspie said in AM612 Passive Infrared Sensor Breakout Board:

for what its worth IIRC i'm getting at least 6 months on the ol' 612 with a CR2450.
Close to two years on a CR123a. So yeah, if I made more I'd design a new board for the new PIR sensors you're finding out there but the 612 even with its higher dropout voltage seems to work fine with even a moderatly sized battery.

Unless the actual current drain is larger than the 14ua I'm assuming, it sounds as though the other drains on your battery are what's dominating. So, if my calculations are right, you likely wouldn't get more than a small percentage more battery life out of using the 3ua sensor instead of the AM612.

[waspie]

@NeverDie said in AM612 Passive Infrared Sensor Breakout Board:

@waspie said in AM612 Passive Infrared Sensor Breakout Board:

for what its worth IIRC i'm getting at least 6 months on the ol' 612 with a CR2450.
Close to two years on a CR123a. So yeah, if I made more I'd design a new board for the new PIR sensors you're finding out there but the 612 even with its higher dropout voltage seems to work fine with even a moderatly sized battery.

Unless the actual current drain is larger than the 14ua I'm assuming, it sounds as though the other drains on your battery are what's dominating. So, if my calculations are right, you likely wouldn't get more than a small percentage more battery life out of using the 3ua sensor instead of the AM612.

I'm using mostly 328p with edbyte radios with a resting current (no PIR) of like lets say 5-7ua? I haven't tested it in forever. with 2 years of battery on a 123 it just didnt seem worth the trouble worrying about any of it. and thanks for your designs that got me off the ground with that stuff btw.

after the fix for the 51822 and 832 i put together a few of those and those are using the cr2450. i think those rest at like 4.5ua (minus the pir of course). 6+ months on a button cell is quite all right with me.