AT32 DAC — 双 DAC 三角波

Tue, 08 Sep 2026 14:52:21 +0800

DAC — 双 DAC 三角波

固件库: AT32F403A_407_Firmware_Library V2.2.2
芯片: AT32
源文件: AT32/AT32F403A_407_Firmware_Library_V2.2.2/project/at_start_f403a/examples/dac/two_dac_trianglewave/src/main.c

功能简介

本示例演示 DAC 输出三角波。利用 DAC 内置的三角波生成器，无需 CPU 干预即可输出三角波。

完整代码

#include "at32f403a_407_board.h"
#include "at32f403a_407_clock.h"

int main(void)
{
  system_clock_config();

  at32_board_init();

  /* turn led2/led3/led4 on */
  at32_led_on(LED2);
  at32_led_on(LED3);
  at32_led_on(LED4);

  /* enable dac/tmr2/gpioa clock */
  crm_periph_clock_enable(CRM_DAC_PERIPH_CLOCK, TRUE);
  crm_periph_clock_enable(CRM_TMR2_PERIPH_CLOCK, TRUE);
  crm_periph_clock_enable(CRM_GPIOA_PERIPH_CLOCK, TRUE);

  /* once the dac is enabled, the corresponding gpio pin is automatically
     connected to the dac converter. in order to avoid parasitic consumption,
     the gpio pin should be configured in analog */
  gpio_init_struct.gpio_pins = GPIO_PINS_4 | GPIO_PINS_5;
  gpio_init_struct.gpio_mode = GPIO_MODE_ANALOG;
  gpio_init_struct.gpio_out_type = GPIO_OUTPUT_PUSH_PULL;
  gpio_init_struct.gpio_pull = GPIO_PULL_NONE;
  gpio_init_struct.gpio_drive_strength = GPIO_DRIVE_STRENGTH_STRONGER;
  gpio_init(GPIOA, &gpio_init_struct);

  /* get system clock */
  crm_clocks_freq_get(&crm_clocks_freq_struct);

  /* (systemclock/(systemclock/1000000))/100 = 10KHz */
  tmr_base_init(TMR2, 99, (crm_clocks_freq_struct.sclk_freq/1000000 - 1));
  tmr_cnt_dir_set(TMR2, TMR_COUNT_UP);

  /* primary tmr2 output selection */
  tmr_primary_mode_select(TMR2, TMR_PRIMARY_SEL_OVERFLOW);

  /* dac1 and dac2 configuration */
  dac_trigger_select(DAC1_SELECT, DAC_TMR2_TRGOUT_EVENT);
  dac_trigger_select(DAC2_SELECT, DAC_TMR2_TRGOUT_EVENT);

  dac_trigger_enable(DAC1_SELECT, TRUE);
  dac_trigger_enable(DAC2_SELECT, TRUE);

  dac_wave_generate(DAC1_SELECT, DAC_WAVE_GENERATE_TRIANGLE);
  dac_wave_generate(DAC2_SELECT, DAC_WAVE_GENERATE_TRIANGLE);

  dac_mask_amplitude_select(DAC1_SELECT, DAC_LSFR_BIT90_AMPLITUDE_1023);
  dac_mask_amplitude_select(DAC2_SELECT, DAC_LSFR_BITA0_AMPLITUDE_2047);

  dac_output_buffer_enable(DAC1_SELECT, FALSE);
  dac_output_buffer_enable(DAC2_SELECT, FALSE);

  dac_dma_enable(DAC1_SELECT, TRUE);
  dac_dma_enable(DAC2_SELECT, TRUE);

  /* enable dac1: once the dac1 is enabled, pa.04 is
     automatically connected to the dac converter. */
  dac_enable(DAC1_SELECT, TRUE);

  /* enable dac2: once the dac2 is enabled, pa.05 is
     automatically connected to the dac converter. */
  dac_enable(DAC2_SELECT, TRUE);

  dac_dual_data_set(DAC_DUAL_12BIT_RIGHT, 0x100, 0x100);

  /* enable tmr2 */
  tmr_counter_enable(TMR2, TRUE);

  while(1)
  {
  }
}

代码讲解

系统时钟初始化：配置 MCU 的主频和时钟树。不同芯片的时钟配置不同，一般由工具生成。

板级初始化：初始化开发板上的 LED、按键等基础外设。

GPIO 配置：设置引脚为输出/输入模式，选择推挽/开漏输出，配置上拉/下拉。

定时器配置：设置预分频器（PSC）和重装载值（ARR），定时时间 = (PSC+1) × (ARR+1) / 时钟频率。

Two_dac_trianglewave on CLing

AT32 DAC — 双 DAC 三角波

DAC — 双 DAC 三角波

功能简介

完整代码

代码讲解