I've got an Arduino/Bluetooth (Bluetooth Bee-Standalone). I've hooked it up with an HC-SR04, it's intended to be mounted at the top of a rain barrel to measure the water depth. What's the best ...

The ArduIMU V4 is an Arduino based integrated measurement unit that offers a complete wireless sensor module that started as an open source project by 3DRobotics back in 2007.

He further explains that, with the Arduino Uno, you can remove the reference capacitor from the circuit, and simply use the stray capacitance present in the board and microcontroller, which can be ...

This project is a great example. [Scott Daniels] takes a look at the other voltage measurement options available to AVR chips used by Arduino.