The Inertial Measurement Unit

The inertial measurment unit (IMU) board for BRB is finally off to BatchPCB. The IMU will interface to a BeagleBoard, which will do the heavy lifting, by TWI.

The IMU is controlled by an ATMega168, and includes a 3-axis LIS3LV02DQ accelerometer, 3-axis gyro consisting of a single-axis LY510ALH and dual-axis LPR510AL, and a 3-axis compass consisting of a single-axis HMC1051ZL and 2-axis HMC1052L. All this for less than (or about) $100.

Schematics are below, starting with the microcontroller and accelerometer (which interfaces with the microcontroller via SPI):


then the compass (with attendant amplifiers and a MOSFET pair for setting and resetting the sensor):


and finally the gyros, for which the full scale will be selectable on the fly as either 400 degrees per second or 100 degrees per second: