A small update with some results on the bedroom floor lighting project.
The small red dot in the center of the image above is where the hardware is (the boxed Arduino) with the PIR to the left. It’s hard to make a picture in almost complete darkness – keeping the picture sharp but also getting a result with colors that match with what my own eyes see is not that easy.. But the picture above resembles what I see when I get out of bed during the night well enough – and it’s exactly what I wanted! The LED strips (1.5 meters on both sides of the bed) light up the floor well enough to spot any obstacles, but it doesn’t light up the whole room. And the 15 seconds turn out to be the right amount of time to light up the floor; and the LDR takes care of unnecessary lighting during daytime; so in one word, the only conclusion can be: perfect!
One small glitch though, which points out the difference between a clean testing environment and usage in real life: some days ago, when I had to change the alarm clock, I switched on the bedside lamp so I could see the buttons on the alarm clock. This triggered the LED strips to go on!
This means that the switching of the 230V lamp resulted in a ‘spike’ on the PIR sensor input on the Arduino… hmm. I think I’ll have to redo some wiring and use shielded cables instead of the unshielded & untwisted ones I’m using right now. My bad…
Perhaps another solution would be to watch the incoming PIR signal on the Arduino more closely and detect whether it’s a short ‘spike’ or not and decide not to turn on the LEDs on a short ‘high’; but that just doesn’t feel right – cables first!