Accelerometers and Gyros

1
Accelerometers and Gyros

• Timothy Friez
• Class 3
• 1/29/08

2
Accelerometer

• The Dual-Axis Accelerometer (DAA) measures both
  vibration and gravity.
• It should be connected to two of the RC analog
  inputs.
• One to measure X-axis acceleration and one to
  measure Y-axis acceleration.

3
Using Accelerometer with ROBOTC

• Connect to two analog inputs (analog inputs 2 and
  3 on our robot)
• Set Motors and Sensor Setup to Accelerometer.

4
Using Accelerometer with ROBOTC

• Access values with
• SensorValuex_axis
• SensorValuey_axis
• Values will range from -200 to 200
• Scale is 100ths of a G
• So a value of 153 would be 1.53Gs
• Sensor will be at rest at or near zero.

5
Gyro Sensor

• The Yaw Rate Gyro sensor is used to determine
  rotation.
• The output labeled T is for Twist or
  rotational velocity.
• The output labeled R is Relative Temperature.
• 80 degrees/sec resolution

6
How to use gyro with ROBOTC

• Connect to one analog input twist only
  (analog input 1 on our robot)
• Set Motors and Sensor Setup to Accelerometer.

7
How to use gyro with ROBOTC

• Access using the command
• SensorValuegyro
• Sensor will give back results in tenths of a
  degree.
• A reading of 900 is actually 90.0 degrees
• The sensor is automatically zeroed at the start
  of your program.