SLAAE50A January   2022  – October 2022 MSP430FR2533 , MSP430FR2533

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2Basic Knowledge and Principles of Self-Inductive Capacitive Touch
  5. 3MSP430FR2533 Liquid Level Measurement Application
    1. 3.1 System Design
    2. 3.2 Hardware Design
    3. 3.3 Software Design
    4. 3.4 Test Results
  6. 4Conclusion
  7. 5References
  8. 6Revision History

Abstract

This application note introduces a system solution for liquid level detection using a capacitive touch MCU. It introduces the basic principles of capacitive touch to detect liquid level. Then it uses MSP430FR2533 capacitive touch MCU to design the system, finish the debugging of the software code, and verify the solution with a bench test. The test results show that the solution can accurately measure the depth of the liquid. Furthermore, four different electrode connection methods and two different capacitance measurement methods are tested and compared. Ultimately, it introduce a software optimization for the large error in small liquid heights.