SNOAA90A february   2023  – may 2023 DRV5033-Q1 , LDC3114-Q1 , TMAG5170-Q1 , TMAG5170D-Q1 , TMAG5173-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Push Buttons
    1. 2.1 Mechanical Buttons
    2. 2.2 Hall-Effect Switches
    3. 2.3 Capacitive Touch Buttons
    4. 2.4 Inductive Touch Buttons
  6. 3Dials, Knobs, and Rotational Selectors
    1. 3.1 Mechanical Dials
    2. 3.2 Hall 3D Linear Dial
    3. 3.3 Encoder Using Hall
    4. 3.4 Encoder Using Inductive
    5. 3.5 Scroll Wheels
    6. 3.6 Rocker Switches
  7. 4Summary
  8. 5References
    1. 5.1 Device Support
    2. 5.2 Related Documentation
  9. 6Revision History

Introduction

Human-Machine-Interface (HMI) comes in many different forms. In a vehicle, this can be anything from a media button, to an air control knob on the center console, to a switch used to control the window. Historically these have been implemented using electro-mechanical contacts in different forms. These contacts can wear down over time as the current flows between two different pieces of metal or when the metal contacts move and rub against each other. New options in contactless sensing, however, can provide a robust solution with a longer lifetime. For push buttons, designers can replace the electro-mechanical contact with a magnet and magnetic sensor, or use an inductive or capacitive touch instead. For rotational sensing, designers can implement absolute angle detection with a magnetic Hall-effect sensor that can also calculate the angle of the magnet to make the implementation easier on the MCU. Designers can also replace encoder applications with magnetic or inductive sensing options depending on the key considerations of the design. Regardless of the application, these conctactless sensing methods can bring a more robust solution that also provides some design flexibility.