Renovation is always a good opportunity to think about some nice automation projects, cause renovating almost always means (partly) breaking down some things and then rebuilding it in a somewhat different way. That’s the right time to do some extra – drilling holes, pulling wires, cable ducts and so forth.
So when we decided to renovate our staircase, I immediately had a great plan: mounting LED strips under the steps to light the stairs. Automatically of course, and with some cool gadgets thrown in as well 😉
I also got the idea to use 2 light barriers at both ends of the stairs to detect that someone is walking up or down the stairs and control all the 12 LED strips independently; so if someone goes upstairs, the LED strips increase in brightness with an interval: starting with the lowest LED strip, going up. And if some goes downstairs, the strips go on from top to bottom. Sounds nice..
OK, but how do I control 12 LED strips independently? And not just on/off, but also in brightness. I didn’t like the idea of using 4 RGB LED controllers, so I started searching for a >12 channel LED controller. After some days I finally got the inspiration I needed – a JeeLabs Dimmer Plug! The Dimmer Plug uses a PCA9635 IC to drive and dim up to 16 LEDs independently.. that should do it! The Dimmer Plug uses I2C to communicate with the outside world, so that shouldn’t be a problem either.
Yesterday evening I soldered a JeeNode, finished the Dimmer Plug (headers etc.), connected 4 3mm LEDS to the Dimmer Plug, uploaded the dimmer_demo sketch from the JeeLib library to the JeeNode and I saw all 4 LEDs doing their own ‘thing’ independently; so far so good.
But why should I use a JeeNode to control the Dimmer Plug? I mean, I have a couple of Raspberry Pi‘s running here, I could just as well use a Raspberry Pi (RPi) for the I2C communication, right? That saves me the hassle of talking from a RPi to the JeeNode, which in turn talks to the Dimmer Plug… so I decided to leave the JeeNode out and connect the Dimmer Plug directly to the Raspberry Pi.
Connecting the Dimmer Plug to the Raspberry Pi will be done in the next couple of days… part 2 of the ‘staircase project‘ !