The InvenSense MPU-6050 sensor contains an accelerometer and a gyroscope in a single chip. It is very accurate, this sensor is used in self balancing robots, drones, smartphones, etc. The sensor uses the I2C-bus to interface with microcontroller.
This is a 4WD IG42 single bearing platform that includes autonomous GPS navigation. A full array of sensors including a Pololu IMU, motor encoders, and a Garmin 18x 5 Hz GPS that work together to provide waypoint navigation with up to 3 meter accuracy.