Staircase project, part 3: Velleman MK120

After my NAS was fixed, I could continue working on some components I need for our staircase renovation. One of those components is the Velleman MK120 Infrared Light Barrier.

But I needed some proof of how well (or not) these light barriers would work, so I did some tests with the soldered kit on my desk. Well, with about 70 cm. between the transmitter and receiver, even moving a forefinger (or cat paws..) through the beam triggered the buzzer. I also did some test to let the IR beams bounce on nearby objects and that did have an effect on detecting objects, but I hope I can minimize that effect.

Domotica should be invisible if possible, so I decided to keep the IR LEDs off the PCB and solder headers instead. This way I can locate the PCB’s somewhere out of sight. Also the buzzer was not soldered on the PCB, but connected with headers and wire (just for testing purpose, it’s really loud!). Now all I need is a good place in the schematic to tap a good signal that I can use on a MCU or maybe a Raspberry Pi; more on that in a future post.

After the positive results of the tests, I moved on and started drilling some holes here and there and pulling wires, so that the only remaining visible items of these light barriers would be the LEDs.

After some exploratory drilling (I hit some steel reinforcements a couple of times…) I found a way to keep the wires out of sight as much as possible. All the holes are drilled now, including those for the LED strips; a total of at least 17 holes were needed to keep all the wires out of sight. Now my wife can start painting all the wooden parts and I can start finishing the steps…

Next: the light barrier as input for my Domotica system – but that post can take a while, cause there’s a lot of manual labor to be done first!

Below some pictures of the progress so far (click for a larger image).
IR Transmitter PCB IR receiver PCB

IR Transmitters working! IR Receiver LED, bottom

Holes for the transmitter LEDs Hole and wires for top light barrier

Hole and wires for top light barrier

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One Response to Staircase project, part 3: Velleman MK120

  1. Pingback: LED Stair Lighting Hack with Raspberry Pi | Homautomation

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