Don and his wife have a two year old daughter. They’re trying to teach her the concept of time, and get her to understand that, perhaps, one o’clock in the morning is not the perfect time of day for play! To help with this, Don has taken an off-the-shelf clock, hacked it around with a Dremel and inserted a ShiftBrite bright LED as a backlight. He’s then hooked it up to a Raspberry Pi which is coded to tell the ShiftBrite what colour it should be depending on the time. Their daughter then knows to associate specific times of day with a colour, like red for sleep, yellow for play. It’s a lovely idea and you can find out more about it on his blog.