A traditional method for checking water height after a flood involved manually marking water levels on a post from a rowboat. Samuel Cox had a better idea: Flood Beacon. He assembled a microprocessor, accelerometer, ultrasonic sensors, rechargeable battery, cellular GSM and GPS into a floating shell created on a 3D printer. The end result is a device that can measure water turbulence via the accelerometer, and water depth with the ultrasonic sensors.
The data, which is sent to Xively, an IoT-specific cloud firm, can be viewed on a mobile app. It took Cox about six weeks and less than $700 to produce a working prototype, something that would have cost more than $10,000 before 3D printing and the advent of do-it-yourself hardware development.