7. DAC

7.1. Overview

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

7.2. 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）

7.3. 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
  

  

7.4. 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.