funkyguy4000:
Okay.
So i'm also curious, what kind of pressure sensor did you use? Like, say i stepped on the left side and then the sensor was in the center. How does the sensor cover the entire step?
100# flexforce pressure sensor.
To ensure that it is activated, I sandwiched the sensor between two 1/16" stainless steel plates. The pressure sensor has a dab of hot glue on each side of it and the plates have dabs of hot glue between each corner. This ensures that even if you step on the outer edge of the plate, it will still transfer pressure to the sensor.
In the breadboard setup, I also experimented with:
-
IR LED emitter and IR detector - this was the most complex solution to set up since the emitter has to blink at 38kHz, be aligned with the detector, and require much more power. It would also be hard to eliminate dog triggering without mounting it high and then it would be hard to make it blend in. -
IR proximity detector - this brought it down to one package to install but it requires a lot of depth to mount making it hard to blend in. The range is only about 36" on it but on a staircase, the width is only 30" so technically would work well. -
PIR sensor - this also would require a lot of depth to mount (~2") although not as much as the IR emitter/detector above. Blending in issue is still there using this. -
Ultrasonic sensor - this could be rigged up two ways for versatility. Either one at the top and bottom shooting across to the other wall or two in the middle of the facing staircase 180° from each other. The advantage of the middle is that I could do an installation of one box housing both of them and could track people on the staircase as well as where they were on the staircase. Theoretically, I could have lit the stair they were on a different color.
I decided on the pressure sensor for simplicity. It was easy to set up and easy to blend in. If after a period of time I discover these don't work as well as I would like, I still have the hardware to implement one of the options mentioned above.