The AR.Drone navigation board embeds 2 x gyrometers, 1 x accelerometer, plus the ultrasound sensors.
The navigation board includes the sensors and a 40 MIPS microcontroller with a fast 12 bits ADC converter. It has 1 x ultrasonic transceiver and 1 x ultrasonic receiver to measure the height of the drone up to 6 metres. The altimeter provides a measure at a 25 Hz rate.
A 3 axis digital MEMS accelerometer is positioned at the centre of gravity of the AR.Drone. The accelerometer is used in a +/- 2g range and digitalized by an on chip 10 bit ADC. Data is sent to the microcontroller, a two axis MEMS gyroscope and a precision piezo electric gyroscope for the yaw measurement and heading control.
Both analogue sensors measure up to 500 °/s, digitalised by the 12bits ADC of the microcontroller. These sensors compose the inertial measurement unit. The fusion of this data allows computing the Euler angles of the AR.Drone. Euler angles are used for stabilisation.
The navigation board software may be upgraded, when you update the AR.Drone software. This kit includes 1 x navigation board and 4 x screws.