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Product Review: Tiny PIR motion sensor

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Has anyone used one of these-- http://www.seeedstudio.com/depot/tiny-pir-motion-sensor-module-p-277.html ?

I bought one on a lark 2 months ago with a larger Seeed order of tools (mainly to test the waters & see how they do as a tools & parts supplier) and just finally got around to playing with it.









Specs are fairly spartan, saying 4.5-20V input with "0,3V" output, 50uA.


The unit has 3 pins -- +, OUT, -.  I tried powering it with 5VDC across + and - and watched the OUT line with a multimeter.  Sure enough, when motion was detected, the OUT line went high to 3.3V (not 5V) for about 1 second... Pretty nice b/c it seems to have some debounce or filtering in its output, it doesn't just flicker but actually holds the CMOS output stable for a bit.  I tried powering it at 3.3V and it still worked but output a ~2.8V signal on OUT.


Seems like it should work fine with the MSP430 so long as you have a 5V source for it.  Actual power draw was around 46uA at rest, ~98uA during the 1-2 seconds when it detected motion and drove the OUT line high, then returned back to 46uA when motion ceased.  I have not integrated this into any carrier boards yet, was just holding it in free air & moving my torso with the sensor pointed at me.


For my own paranoia's sake, I'll probably include a 1K ohm inline to the OUT signal in case the signal somehow spikes above 3.3V (to protect the protection diodes on the MSP430).


Seems like an overall good option, will report back when I actually use it "in the field".  I think a proper motion sensor bug with nRF24L01+ could be doable here.



It looks like the onboard circuits run at 3.3V b/c there's an SMD IC labeled "7133-1", looking it up it appears to be a 3.3V/30mA voltage regulator which supports up to 24Vin -- http://pdf1.alldatasheet.com/datasheet-pdf/view/64471/HOLTEK/HT7133-1.html -- so I can probably desolder that or short the Vin to Vout leads for native 3V operation.  Sounds like there's no need for a limiting resistor on the OUT line since it runs at 3.3V natively.


I assume the "CDS" empty pins are for a CDS diode light sensor, no idea what happens when you add one to it.  Very little documentation for the device.

Markings on the IC - BISS0001 and YDATN3Q, CDS left pin (right pin is in the GND plane, so the left pin is probably +) goes to pin#9 of that IC.

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IC details - http://www.chinaenbon.com/products/electro-optical-parts/integrated-circuit-ic/integrated-circuit-ic-biss0001.html

Datasheet -- much better: http://cdn.shopify.com/s/files/1/0038/9582/files/BISS0001.pdf


Input voltage 3-5V.  So a remote sensor bug should probably have a boost converter to ensure >=3.0V operation throughout the battery life, in theory.  Probably works fine in practice (it seemed to at ~2.8V) but who knows about performance.


Pin#9 is "Trigger disable input", sounds like it modifies the circuit so it's only armed in the dark.

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