Compass Belt

Over the last week I have been assembling a compass belt. It is a belt lined with ten motors controlled by an arduino. The motor closest to north vibrates so that the person wearing the belt always knows which direction is north. I am not the first person to build a compass belt:

• Wired magazine article
• North Paw directional anklet kit
• Haptic compass

Here is a list of all the parts I used:

• 10 motors $49.50
• Compass $34.95
• Arduino Uno $29.95
• Soldering iron $9.95
• Belt $8.99
• Soldering iron stand $5.95
• Wire $5
• Multiplexer $4.95
• Wire strippers $4.95
• USB cable $3.95
• Breadboard $3.95
• Battery holder $2.95
• Flush cutter $2.95
• Proto boards $2.50
• Solder wick $2.49
• Solder $1.95
• Headers $1.50
• transistor $0.75
• capacitor $0.25
• 1k resistor $0.25
• 33 ohm resistor $0.25
• diode $0.15

Total cost: $174.13 (although a subset of this cost is for tools - just the belt components would be $143.89). Thanks to dllu for helping me design the circuit. It turned out to be a lot more time consuming to build than I was anticipating. I blame it mostly on the terrible soldering iron (which doesn't get hot enough). Here I am wearing the belt:

Here is a picture of the inside:

The belt seems to work well - it is quiet, accurate, and updates instantly when I turn around. I haven't actually found it useful yet - it seems pointless to wear it in places that I am already familiar with (and it looks silly). Even if I don't end up using it, it was fun to build and I learned a lot about electronics.