A little Arduino project to log temperature and humidity, seen here being prototyped along with an interesting set of LEDs.
There are two projects being prototyped here. One is simply interesting lighting, while the other started as an idle question about the efficiency of air-drying clothes vs using a tumble dryer.
Initial prototype, just displaying current temperature (red, scale 0-30°C) and humidity (blue, scale 30-70%). The pink pixels are both red and blue.
This project actually reacts when you stare at it (as you're breathing on the humidity sensor).
The aim of these (other than simply amusement) is to learn a bit of electronics
Before connecting the LEDs, I'd calculated the power consumption (200mA peak) and checked that it's OK for both the USB host and the Arduino. What I hadn't considered was how bright 1W of LEDs is - on the "equivalent tungsten lightbuild" scale it's around a 20W bulb.
The first prototype shown above didn't guard against the LEDs' power line becoming disconnected and them drawing current from the data line. Knowledge was gained at the cost of an LED and, more importantly, the smoothness of a demo.