Having a wee bit of fun today, building an Arduino contraption. It is Father’s Day here (Gawd, can’t they even standardize that?) today, and since I don’t own a Bollerwagen, I thought I’d hack something together. The value on the 7 segment LED display is set with the switch on the top of the board: pressing that, increments a counter which starts at zero, does 1 – 8, and then A for “all”. The eight white LEDs on the bottom right (a bit hard to see on the photo, but there are eight of them) are toggled on or off by the bottom switch, depending on the counter on the 7-segment LED. 0 turns all off, A turns them all on, and other LEDs are toggled on/off when this switch is pressed. The 7-segment display and the eight LEDs are each driven by 74HC555 as described in Serial to Parallel Shifting-Out with a 74HC595, and I’m pleased to say that setting that up was easier that I thought it would be. :-)