Lego PIR Housing

Recently I decided to make a motion triggered camera using RaspberryPi. I wanted to use the SmartiPi RaspberryPi case for the project and ordered it with the camera housing, but I still needed to mount my Passive Infrared Sensor (PIR). So sat down with my son's Legos (which he inherited from me) and came up with this.

You will need the following bricks. I used the Pick a Brick service from Lego to order mine after I prototyped it with my son's bricks.

Lego Bricks:

• Plate 1x6 Part# 4211438 Qty x4
• Plate 2x3 Part# 4211396 Qty x1
• Plate 2x4 Part# 4211395 Qty x4
• Plate 2x6 Part# 4211452 Qty x1
• Plate 1x2 Part# 4211398 Qty x2
• Plate 1x4 Part# 4211445 Qty x5
• Brick 1x3 Part# 4211428 Qty x4
• Brick 1x6 Part# 4211393 Qty x2
• Brick 1x6 with side holes Part# 4211466 Qty x2

Misc:

• PIR Sensor (I used these)
• Female to Female GPIO Jumper Cables

As with typical Lego instructions I'll let the pictures speak for themselves. Of course, I'll add notes where I think they are needed.

Make sure the pins line up with the hole in the bottom. I did have to use a little bit of sandpaper on the board here where it wasn't cut quite straight. I only had to sand away a little bit of extra material to make it fit.

Use a rotary tool (Dremel) or Exact-o Knife to carefully remove part of two of the 2x4 planks as shown. It won't take much. Just enough to accommodate the PIR.

But wait! doesn't this limit the PIR's field of view?! Yes, but in this application I wanted to make sure the subject was in front of the camera. The FOV could be narrowed even further by adding more bricks around the opening.

Remember that bit that wasn't connected at first? Here's why. Although it is possible to connect our wires through the hole in the bottom, this part can easy be removed and put back to make connecting the wires easier.