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

3.2 Differences Between USS and USS_A Module

The SNR of the receive signal is much lower in gas meter than in water meter application. Noise is a problem that cannot be ignored especially in gas meter. Use different approaches to solve the noise issue on both the hardware and software side for gas meter application. The method for software was described earlier, and the differences in the hardware side are described below.

From the table, the USS_A module can be used in gas meter applications. The major difference between the USS and USS_A module is the Sequencer for Acquisition, Programmable Pulse Generator, and Physical Interface (SAPH module).

SAPH: Consists of an extended pulse generator, a low-impedance output driver, an input multiplexer, an acquisition sequencer and external bias terminals.

The SAPH_A module can generate multitone. The output pulses consist of multiple phases. The multitone feature is important for the absTOF calculation in gas meter applications. The binary pattern of the generated excitation signal is used to filter out noise on the UPS, DNS ADC capture signal before processing the Hilbert transform. This multitone feature lowers the impact of noise signal and makes the ADC approach successful when used in gas meter applications.