SLAAES9 March   2025 MSP430FR5043 , MSP430FR6005 , MSP430FR6007 , MSP430FR6043 , MSP430FR6045 , MSP430FR6047

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Flow Meter Measurement Theory
    1. 2.1 TOF Measurement Algorithm Implementation
      1. 2.1.1 AbsTOF Calculation Method – Lobe
      2. 2.1.2 AbsTOF Calculation Method – Hilbert Wide
      3. 2.1.3 dTOF Calculation Method - Cross-Correlation
        1. 2.1.3.1 Get a High-Precision dTOF Result
        2. 2.1.3.2 Optimization in Cross-Correlation Method
    2. 2.2 Differences between ADC Approach and TDC Approach
  6. 3MSP430 MCUs for USS Application
    1. 3.1 USS Module
    2. 3.2 Differences Between USS and USS_A Module
    3. 3.3 Software Implementation on MSP430 MCUs
  7. 4Hardware Design Flow
    1. 4.1 Schematics
      1. 4.1.1 Water Meter Schematic – MSP430FR6047 and MSP430FR6007
      2. 4.1.2 Water Meter Schematic – MSP430FR6043 and MSP430FR5043
      3. 4.1.3 Gas Meter Schematic – MSP430FR6043 and MSP430FR5043
    2. 4.2 PCB Layout Guide
  8. 5Software Design Guide
    1. 5.1 USS Demo Projects and Related Resources
    2. 5.2 Demo Project Instruction
      1. 5.2.1 Files in Demo Project
      2. 5.2.2 Properties Setting in Demo Project
  9. 6Summary
  10. 7References

4.2 PCB Layout Guide

General PCB guidelines need to be followed to make sure of accurate measurements and proper operation.

  1. Decoupling capacitors must be placed close to the supply pins.
  2. Oscillators must be placed close to the chip and use a separated ground plane from the main ground plane. These components be tied to the main ground with a small connection as shown in Figure 4-3. A good ground layout for the crystals can help on getting a higher ESD grade.
    Oscillator Layout Example Figure 4-3 Oscillator Layout Example
  3. Traces for USS CH0_IN, CH0_OUT, CH1_IN, and CH1_OUT must be matched in length to make sure of proper timing of signals because these are in the picosecond range, as shown Figure 4-4.
    USS Signal Layout Example Figure 4-4 USS Signal Layout Example
  4. 1% component tolerance must be used for all USS signal components for highest accuracy.
  5. Make sure that no traces are crossing the USS signal on other layers.
  6. LCD connections must be made following the guidelines in the Designing With MSP430 and Segment LCD application note.