SLAA361A July   2007  – August 2018 MSP430F169 , MSP430F169 , MSP430FG4618 , MSP430FG4618

 

  1.   Speech and Sound Compression and Decompression With MSP430™ MCUs
    1.     Trademarks
    2. 1 Introduction
    3. 2 Compression and Decompression Algorithms
      1. 2.1 Differential Pulse Code Modulation (DPCM)
      2. 2.2 Adaptive Differential Pulse Code Modulation (ADPCM)
    4. 3 Signal Chain on Chip in MSP430 MCUs
      1. 3.1 MSP430F169 Signal-Chain-on-Chip Solution
      2. 3.2 MSP430FG4618 Signal-Chain-on-Chip Solution
    5. 4 Performance on the MSP430 MCUs
      1. 4.1 Using the Associated Code
    6. 5 References
  2.   Revision History

1 Introduction

Sound recorders are implemented with relative ease on microcontrollers (MCUs) that have an integrated analog-to-digital converter (ADC). A microphone followed by an amplifier captures the sound, which is fed to the analog input of the ADC. The recorded sound can then be stored in memory (flash or RAM). A button press can trigger the MCU to play the recorded sound. To play the sound, software moves the stored data to a digital-to-analog converter (DAC) followed by an audio power amplifier.

Such a sound recorder can be easily realized using the MSP430 MCUs. The MSP430 MCU takes advantage of the integrated peripherals to form an on-chip analog signal chain. In addition, the CPU of the MSP430 is powerful enough to perform compression of the recorded sound.

This application report and the accompanying code uses the MSP430FG4618 microcontroller and the MSP430F169 microcontroller for demonstration purposes. The concepts and code in this application report apply to any MSP430 MCU that has at least one ADC input and a DAC.