8. DAC

8.1. Overview

This example shows DAC conversions and waveform display in three working modes.

8.2. Board Setting

• Output voltage at the specified pin. （Please refer to Pin Description ）

• If necessary, connect a jumper for VREF pin according to the HW design. （Please refer to Pin Description ）

8.3. Running the example

• Running log is shown in the serial terminal as follows

  This is a DAC demo:
  1. Direct mode
  2. Step   mode
  3. Buffer mode
  Please enter the DAC mode code:
  

• Select one of DAC working modes to start DAC conversion, and then observe the waveform through an oscilloscope

  • Direct mode

    Please enter the DAC mode code: 1
    Set DAC to output data in direct mode
    DAC is outputting a triangle waveform in direct mode
    

    

  • Step mode

    Please enter the DAC mode code: 2
    Set DAC to output data in step mode
    DAC is outputting a saw tooth waveform in step mode
    

    

  • Buffer mode

    Please enter the DAC mode code: 3
    Set DAC to output data in buffer mode
    DAC is outputting a sine waveform in buffer mode
    

    

8.4. Note

• Exception exit

  1. In step mode or in buffer mode, press the “space” key to abort the test, and then a test mode can be reselected.

  2. In direct mode, press the “space” key to abort the loop after the test is finished, and then a test mode can be reselected.