/**
  **************************************************************************
  * @file     readme.txt
  * @version  v2.0.4
  * @date     2021-12-31
  * @brief    readme
  **************************************************************************
  */

  this demo is based on the at-start board, in this demo, shows how to use
  the adc1 internal channel17 to check vref value.
  the trigger source is software
  the convert data as follow:
  - adc1_ordinary_value ---> adc1_channel_17
