Description: This is a simple to use motion sensor. Power it up and wait 1-2 seconds for the sensor to get a snapshot of the still room. If anything moves after that period, the ‘alarm’ pin will go low.
This unit works great from 5 to 12V (datasheet shows 12V). You can also install a jumper wire past the 5V regulator on board to make this unit work at 3.3V. Sensor uses 1.6mA@3.3V.
The alarm pin is an open collector meaning you will need a pull up resistor on the alarm pin. The open drain setup allows multiple motion sensors to be connected on a single input pin. If any of the motion sensors go off, the input pin will be pulled low.
We’ve finally updated the connector! Gone is the old “odd” connector, now you will find a common 3-pin JST! This makes the PIR Sensor much more accessible for whatever your project may need. Red = Power, White = Ground, and Black = Alarm.
Based on 7 ratings:
3 of 4 found this helpful:
(1) Signal wire is black, ground wire is white.
These should be reversed. I might have killed two of my sensors because the wire colors don’t match up to expectations.
(2) The manual says that there should be a 10k pullup resistor on the arduino, why can’t this be built into the electronic itself? The power rail is right there.
There are other PIR sensors on the market. Stay away from this one.
Hi, Pin outs for this sensor are clearly listed in the product description. (Red = Power, White = Ground, and Black = Alarm.) Sorry that this color pattern is not satisfying for you. As for the pull up resistor, some processors have built in pullup resistors. So leaving the sensor bare allows for a wider range of applications.
Be careful, the wire colors vary. I bought two from Sparkfun and on one of them them the Alarm wire color is white and on the other one it is black.
Our Tech Team has only seen this happen one other time. If you would like an exchange, please let us know. We’ll be happy to help you. Thanks
This sensor works well, is a good value and was delivered quickly. I used it to trigger an Arduino with a sound shield. It works with the Arduino very well and although other people have had issues with it, I had none. I used the Arduino pinMode(INPUT_PULLUP) that uses the internal 20K pull up resistor so you do not need any external resistor. The project I used this for was a pumpkin that made sounds as people approached. It was a hit.
Thanks for reminding me that it has awkward color coding for the cables. It is something that definitely can be/should be fixed for a sensor priced at $10 dollars. The cable should not be advertised as a new feature until the color coding is fixed.
I bought two sensors. The sensors work but it can be more consistent and sensitive. Sometimes it would recognize a hand quickly, sometimes its totally ignored. I am not sure if its picking up the reflection of IR in the room so when a hand is placed closely to the front of the sensor, it still would not register a “change”.
This motion sensor’s detection distance is horrible. I connected it to my Arduino and it only senses it if I’m touching it or like 1 millimeter away…
It sounds like you have a bad unit, or a connection issue. Please contact our support team and they’ll be happy to help you out.
i had it hooked up to an LED and it was flashing like crazy whether there was motion or not. Then I found this site http://bildr.org/2011/06/pir_arduino/ and added the resistor and the code from the site. It stlill didn’t work, there was no output on the screen saying “motion detected” I am using an Arduino uno, any ideas as to what I’m doing wrong? Thanks in advance. I’ve loved all the other products I’ve ordered from you including the Drum kit Kit ai - I got that working without any problem.
Hi, It sounds like you should get in touch with our Technical Support team. They’ll be happy to try to help you get up and running. Tech support @ sparkfun .com
Well maybe I just don’t know how to use this thing.
But it seems to be a real pain to use. First off is the black wire is the “alarm”. Maybe because it is an open collector that is a reasonable color choice. I forgot at least once that it was an open collector and had to rewire.
Once I got it detecting it did fine signalling someone entered the room. But I could not figure out a way to find out once someone entered if they left. I have a complicated filter and state machine in code to try and remove the invalid blurps. It looks like after so much inactive time it sends a pulse on the alarm.
I think I will give up and search for something else, maybe buy some motion activated night lights and use them in my project.