NEW PRODUCTS – Mini Basic PIR Sensors – BL412 + BS412

4667 comparison ORIG 2020 08

NEW PRODUCTS – Mini Basic PIR Sensors – BL412 + BS412


PIR sensors are used to detect motion from pets/humanoids from about 5 meters away (possibly works on zombies, not guaranteed). This sensor is much smaller than most PIR modules, which makes it great for unobtrusive projects. It’s also fully-contained – only needs power, ground, and a resistor to set the delay time – and breadboard or perfboard friendly.

4667 iso 01 ORIG 2020 08

Runs on 3.3V power – so make sure if you’re interfacing with an Arduino or other 5V chip, you power it from the 3V regulator. Digital signal output is 3.3V high/low and you can change the length of time the signal pin stays high by connecting a resistor divider to the second pin, from 2 seconds (0V) up to one hour (3.3V) – see the datasheet ‘on time’ table for recommended resistor values.

To use, see datasheet page 7 pin-out diagram:

  • Connect pin #1 to ground
  • Connect pin #2 to ground (on time of 2 seconds)
  • Connect pin #3 to 3.3V
  • Check signal on pin #4

The snap-on lens is focused to 5 meters away with a 120 degree spread, but should work from about 3 to 8 meters. These are smaller and less expensive than our PIR modules, and you’ll find the performance is OK but not as great as the larger modules, for example not having as wide of a range and taking longer to trigger.

4667 iso 02 ORIG 2020 08

For a PIR tutorial with CircuitPython and Arduino code examples and project ideas, check out our PIR sensor tutorial page!

The BL sensor window is 5mm x 3.8mm. We also carry the BS412 PIR sensor which has a smaller sensing element.

4667 detail ORIG 2020 08

Now for the BS412!


PIR sensors are used to detect motion from pets/humanoids from about 5 meters away (possibly works on zombies, not guaranteed). This sensor is much smaller than most PIR modules, which makes it great for unobtrusive projects. It’s also fully-contained – only needs power, ground, and a resistor to set the delay time – and breadboard or perfboard friendly.

4666 BS412 iso 01 ORIG 2020 06

Runs on 3.3V power – so make sure if you’re interfacing with an Arduino or other 5V chip, you power it from the 3V regulator. Digital signal output is 3.3V high/low and you can change the length of time the signal pin stays high by connecting a resistor divider to the second pin, from 2 seconds (0V) up to one hour (3.3V) – see the datasheet ‘on time’ table for recommended resistor values.

To use, see datasheet page 7 pin-out diagram:

  • Connect pin #1 to ground
  • Connect pin #2 to ground (on time of 2 seconds)
  • Connect pin #3 to 3.3V
  • Check signal on pin #4

The snap-on lens is focused to 5 meters away with a 120 degree spread, but should work from about 3 to 8 meters. These are smaller and less expensive than our PIR modules, and you’ll find the performance is OK but not as great as the larger modules, for example not having as wide of a range and taking longer to trigger.

4666 BS412 iso ORIG 2020 06

For a PIR tutorial with CircuitPython and Arduino code examples and project ideas, check out our PIR sensor tutorial page!

The BS sensor window is 4mm x 3mm. We also carry the BL412 PIR sensor which has a larger sensing element (so it will be more sensitive).

4666 BS412 detail 01 ORIG 2020 06

4666 BS412 quarter ORIG 2020 06

In stock and shipping now!


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