Pigeon 2.0 User’s Guide ___ www.ctr-electronics.com ______________________ 1/31/2022
Cross The Road Electronics Page 2 ____________________________ 1/31/2022
Table of Contents
1. Device description .....................................................................................................................................................5
1.1. Kit Contents........................................................................................................................................................5
1.2. Features..............................................................................................................................................................6
1.3. Electrical/Inertial Specifications.........................................................................................................................7
1.4. General/Mechanical Specifications....................................................................................................................7
1.5. LED States...........................................................................................................................................................8
1.6. Functional Diagram ............................................................................................................................................9
1.6.1. Mount Orientated Signals...........................................................................................................................9
1.6.2. Enclosure Orientated Signals ......................................................................................................................9
1.7. Changes between Pigeon 1 and Pigeon 2 ........................................................................................................10
2. IMU Error Sources....................................................................................................................................................11
2.1. Location –Center of Rotation ..........................................................................................................................11
2.2. Temperature ....................................................................................................................................................11
2.3. Gyroscope Sensitivity Error ..............................................................................................................................12
2.4. Avoid Magnetic/Ferromagnetic materials .......................................................................................................13
2.5. Vibration...........................................................................................................................................................14
2.6. Saturated inputs...............................................................................................................................................14
3. Calibration ...............................................................................................................................................................15
3.1. Temperature Calibration..................................................................................................................................15
3.2. Gyroscope Bias Calibration...............................................................................................................................15
3.3. Gyroscope Sensitivity Calibration.....................................................................................................................15
3.4. Accelerometer Calibration ...............................................................................................................................15
3.5. Compass Calibration.........................................................................................................................................15
4. Boot behavior ..........................................................................................................................................................16
4.1. Boot behavior - Test Results ........................................................................................................................17
5. Wiring ......................................................................................................................................................................19
6. Orientation Convention...........................................................................................................................................20
6.1. World Frame Reference.............................................................................................................................20
6.2. Euler Angles................................................................................................................................................20
6.3. Gimble Lock................................................................................................................................................20
6.4. Does X/Y Axis placement matter?..............................................................................................................21
6.5. Default Mounting Orientation ...................................................................................................................21
6.6. Custom Mounting Orientation...................................................................................................................21
6.6.1. Custom Mounting Orientation –Explicit Values ...............................................................................22
6.6.2. Custom Mounting Orientation –Phoenix Tuner ...............................................................................23
7. FAQ ..........................................................................................................................................................................24
