💬 nrf52832 PIR

[openhardware.io]

https://www.openhardware.io/view/691/nrf52832-PIR

[NW27]

What exactly is this?

[waspie]

its the start of a nrf52832-based motion sensor similar to neverdie's Multi-Sensor: Temp/Humidity/PIR/ Leak/Magnet/Light/Accel seen here:
https://www.openhardware.io/view/510/Multi-Sensor-TempHumidityPIR-LeakMagnetLightAccel

The nrf51822 is a bit finicky. I made it slightly bigger to accommodate a cr2450 and use a nrf52832 which is allegedly more reliable for low power sensors. I have a PIR hat, too, that i need to upload. I made my version adjustable. Neverdie's version works, but, the pir triggers quite a lot at the minimum reset time which means its triggering often in a busy room which uses a lot more battery.

[waspie]

I'll be updating this with pictures of actual boards soon, including my PIR "hat"

I've been running several of them for about two months now on a single CR2450 (~620mah) and they're still showing just slightly over 3 volts. These are detecting motion many times per hour during the day.

[waspie]

Some pictures of an assembled unit with 3d printed case

[berkseo]

@waspie
Hello, great project! Can you provide a link to the datasheet of the pir sensor?

[Nca78]

@waspie nice, with this case color you should get black fresnel lenses, it would look great :)

@berkseo I guess it's an AM612, you will easily get datasheet on google

[berkseo]

@nca78 said in 💬 nrf52832 PIR:

AM612

I thought something more original than AM612. It has a supply voltage of 2.4-3.2V, if I'm not mistaken.

[Nca78]

@berkseo said in 💬 nrf52832 PIR:

@nca78 said in 💬 nrf52832 PIR:

AM612

I thought something more original than AM612. It has a supply voltage of 2.4-3.2V, if I'm not mistaken.

No it's 2.7-3.3, which is not great for button cell as a fair share of the capacity will not be available.

[waspie]

Yeah, it's an AM612. I think when I originally put this together I didn't realize the low cutoff voltage :|

We'll see how long it lasts...
I guess options then are to add a buck converter or strap AAAs on the back instead

Black fresnel lens? what?? I might have to find some of those

[Nca78]

@waspie said in 💬 nrf52832 PIR:

Black fresnel lens? what?? I might have to find some of those

They are on Aliexpress. Not even expensive.

[berkseo]

@waspie said in 💬 nrf52832 PIR:

Yeah, it's an AM612. I think when I originally put this together I didn't realize the low cutoff voltage
We'll see how long it lasts...
I guess options then are to add a buck converter or strap AAAs on the back instead
Black fresnel lens? what?? I might have to find some of those

...search on aliexpress

[waspie]

thanks guys, i just ordered a few :)
@berkseo i was searching for buck/boost converters and found TPS61098 which when i searched for turned up on one of you designs :)

what i can't figure out just yet is how to wire it up for our application. can you shed any light on that, please?

well, i think i may have sorted it.... GND and MODE to ground. VSUB is 3.3 (or 3v if i do the 61098) out (not being used in this application?).

SW inductor, vin of course, and vmain is the output for the mcu i think

[Nca78]

@berkseo said in 💬 nrf52832 PIR:

Are these for the S16 smd sensors ? If yes, can you please give me a link of where you ordered them ? I couldn't get any, LCSC sold me the sensors but refused to order the lenses for me, and Senba can send them "for free" but with a very high express shipping fee.

[berkseo]

@nca78 said in 💬 nrf52832 PIR:

Are these for the S16 smd sensors ? If yes, can you please give me a link of where you ordered them ? I couldn't get any, LCSC sold me the sensors but refused to order the lenses for me, and Senba can send them "for free" but with a very high express shipping fee.

Only through Alibaba (not aliexpress) at Senba (((

[berkseo]

@waspie
TPS610981DSE, see table in datasheet, paragraph 5
I use the schema from the datasheet, paragraph 9.2.2

[berkseo]

I would like to find an available pir sensor powered by 1.8 V :(

[waspie]

@berkseo said in 💬 nrf52832 PIR:

I would like to find an available pir sensor powered by 1.8 V

yeah, that'd be nice

[waspie]

5 months and voltage still holding decently high
/77/28/1/0/38 2.964