A few weeks ago, I came up with an idea for a new Arduino project. The concept is and execution should be pretty simple: Hook up an accelerometer with some LEDs using an Arduino board. Stick this little gadget in a toy car and use the accelerometer to measure the speed that the car is traveling. Based on the speed, the LEDs will light up different colors along a gradient, say, red/orange for slow, yellow/green for medium, and blue/purple for fast. When you drive the car around, you can tell (relatively) how fast it’s going by the color your LED speedometer is shining.
I submitted this idea to quirky.com a few days ago with a slightly different idea (same gadget in a ball that you can kick around — see the quirky link), and it’s gotten some decent traction, though probably not enough to actually be produced.
Still, I think this is a cool idea for a toy and, as soon as the accelerometer I ordered gets here, I’m going to try to make a prototype. Might be a cool kids’ toy — could be put in a toy vehicle or ball, but also as a clip that you could attach to your bike or clothing to see how fast you’re going — a sort of visual speedometer.