ArduPilotMega and qGroundControl for testing
ArduPilotMega (APM) is a very capable Auto Pilot solution based on an ATmel2650 micro controller and a powerful and complete software solution for fixed wing, helicopter and multi-copter aircrafts. Various sensor solutions are available and supported (gyro, accelerometer, barometric altimeter, pitot speed, gps, range sensors, telemetry comm, magnetometer, etc.).
qGroundControl lets you control your UAV/drone from software over various communication methods (wifi, bluetooth, GSM, USB, etc.). Communication between UAV and ground control software is achieved with the MAVLink protocol.
I have written a mini howto on how to setup ArduPilotMega and qGroundControl for testing sensor data of APM with qGroundControl with a USB connection.