SLYU064A June   2023  – December 2023 TMAG3001 , TMAG5170 , TMAG5170-Q1 , TMAG5170D-Q1 , TMAG5173-Q1 , TMAG5253 , TMAG5273

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Joystick Design
    1. 2.1 Establishing Form Factor
      1. 2.1.1 Choosing Mechanical Implementation
      2. 2.1.2 Choosing Magnetic Implementation
    2. 2.2 Magnet Sensor Placement
    3. 2.3 Design Calculations
    4. 2.4 Post Processing
    5. 2.5 Prototyping and Bench Testing
    6. 2.6 Error Sources
      1. 2.6.1 Mechanical Hysteresis
      2. 2.6.2 Nearby Material Influence
      3. 2.6.3 Fulcrum Slippage
      4. 2.6.4 Offset
  6. 3Lever Design
    1. 3.1 Establishing a Form Factor
      1. 3.1.1 Choosing Mechanical Implementation
    2. 3.2 Magnet Sensor Placement
    3. 3.3 Design Calculations
    4. 3.4 Prototyping and Bench Testing
    5. 3.5 Error Sources
  7. 4Summary
  8. 5References
  9. 6Revision History

2.6.1 Mechanical Hysteresis

Friction coupled with the modulus of elasticity were found to contribute mechanical hysteresis for the 2 sensor 2 magnet thumbstick tested in this application note. Consequently, the stick component appeared to be moving while the magnet was not, resulting in movement similar to what is shown in Figure 2-22 where the left thumbstick is in the default resting position with the magnet centered as expected while for the right thumbstick the stick is tilted to the left but the magnet has not moved by any discernible amount. Part tolerances and materials with a low coefficient of friction are important for minimizing this error.

GUID-20230512-SS0I-NGKN-HJSF-8MPJ1MMNJGGQ-low.svg Figure 2-22 Mechanical Hysteresis