1. Ryan Roberts
Gyroscopes

2. Background
A Gyroscope is a device used for measuring or maintaining orientation, based on angular momentum.
Gyroscopes have been around for over a century now and what were once used as toys are now used as an instrument everywhere from airplanes for stabilization to smartphones for screen orientation.

3. How Gyroscopes Work
A gyroscope in operation with freedom in all three axes. The rotor will maintain its spin axis direction regardless of the orientation of the outer frame.

4. Precession in Gyroscopes
When a force is applied to the top of the gyroscope you would think it would fall over due to gravity, but because it is spinning it stays upright; the effect of this is the cause of precession.
Precession is a change in the orientation of the rotational axis of a rotating body.

5. Mechanical Gyroscopes
Consist of a spinning wheel or disc in which the axle is free to assume any orientation.
Mostly found as a toy on the market
Consist of large amounts of mass
Large scale are expensive or unavailable

6. Electronic Gyroscopes
Sense rotational motion
Sense changes in orientation

7. MEMS Gyroscopes Most MEMS Gyroscopes use a tuning fork configuration
MEMS – A Micro electrical mechanical system.
Most MEMS Gyroscopes use a tuning fork configuration

8. MEMS Gyroscopes
When the Gyro is rotated , a small resonating mass is shifted as the angular velocity is changes. The movement is converted into very low-current electrical signals that can be amplified and read by many microcontrollers.

9. MEMS Gyroscope Applications
MEMS are not a specific type, but a class of gyroscopes that are printed onto circuit boards.
High Performance and low power consumption
Mass Produced at Low Cost
Used in Phones and printed on circuit board for use in many other applications

10. Gyroscope Breakout Boards
3-Axis ±250 / 500 / 2000° / s Gyro Sensor L3GD20 $11.50
• Operating Voltage: 2.5 V to 5.5 V
• Carrier/breakout board for the ST L3GD20 three-axis gyroscope
• Supply current: 7 mA
• Sensitivity range (configurable): ±250º/s, ±500º/s, or ±2000º/s

11. Gyroscope Breakout Boards
Triple-Axis Digital-Output Gyro Breakout - ITG $24.95
Digital-output X-, Y-, and Z-Axis angular rate sensors (gyros) on one integrated circuit
Wide VDD supply voltage range of 2.1V to 3.6V
three 16-bit analog-to-digital converters (ADCs) for digitizing the gyro outputs, a user-selectable internal low-pass filter bandwidth, and a Fast-Mode I2C (400kHz) interface.
embedded temperature sensor and a 2% accurate internal oscillator

12. Gyroscope Breakout Boards
SparkFun Triple Axis Accelerometer and Gyro Breakout - MPU $39.95
Combining a MEMS 3-axis gyroscope and a 3-axis accelerometer on the same silicon die together with an onboard Digital Motion Processor
Tri-Axis angular rate sensor (gyro) with a sensitivity up to 131 LSBs/dps and a full-scale range of ±250, ±500, ±1000, and ±2000dps
Tri-Axis accelerometer with a programmable full scale range of ±2g, ±4g, ±8g and ±16g

13. Conclusion
The best gyroscope for use in our skiing robot project would be the SparkFun Triple Axis Accelerometer and Gyro Breakout - MPU-6050
The accelerometers will be used for tilt-sensing. Because they are affected by the acceleration of gravity, an accelerometer can tell you how it’s oriented with respect to the Earth’s surface.
The gyroscope will be used to monitor the orientation of the object in motion, an accelerometer may not give you enough information to know exactly how it’s oriented. Unlike accelerometers gyros are not affected by gravity, so they make a great complement to each other.