Building an electronic advent wreath with an Arduino Uno
The motivation: It was Christmas season and there is the obligatory waiting time between December 1st and December 24th until you can stuff yourself with enormous amounts of food and unwrap some presents and then complain about the weight gain that noone saw coming. To pass that time a little faster, you usually have an advent wreath and light a candle every seven days. As we were eager to stuff our bellies but were not allowed to light candles at our workplace, due to fire protection, a friend of mine and I decided to build an electronically controlled advent wreath. Instead of candles, we decided to use LEDs – Less fire, less problems. And as we are lazy engineers we wanted the thing to light the LEDs by itself, when it was the right time. The hardware requirements: Basically all you need is something, that tells you the time and something that lights LEDs. We decided to go with a DS1307 RTC module, as it features the I2C protocol and has an excellent Arduino library ava...