本帖最后由 dql2015 于 2023-3-24 16:30 编辑
avr64dd32支持DAC功能，分辨率达10bit，内置基准电压，在要求不高的场合生成模拟信号足够。
官方提供了测试例程，打开MPLAB X IDE v6.05编译烧录到开发板上，PD6管脚就能输出正弦波了。
- 6#include "mcc_generated_files/system/system.h"
- #include <math.h>
- #include <util/delay.h>
- /* Number of samples for a sine wave period */
- #define SINE_PERIOD_STEPS (100)
- /* Sine wave amplitude */
- #define SINE_AMPLITUDE (511)
- /* Sine wave DC offset */
- #define SINE_DC_OFFSET (512)
- /* Frequency of the sine wave */
- #define SINE_FREQ (50)
- /* Step delay for the loop */
- #define STEP_DELAY_TIME ((1000000 / SINE_FREQ) / SINE_PERIOD_STEPS)
- /* Buffer to store the sine wave samples */
- uint16_t sineWave[SINE_PERIOD_STEPS];
- static void sineWaveInit(void)
- {
- uint8_t i;
- for(i = 0; i < SINE_PERIOD_STEPS; i++)
- {
- sineWave[i] = SINE_DC_OFFSET + SINE_AMPLITUDE * sin(2 * M_PI * i / SINE_PERIOD_STEPS);
- }
- }
- /*
- Main application
- */
- int main(void)
- {
- uint16_t sineIndex = 0;
-
- /* Initializes MCU, drivers and middle-ware */
- SYSTEM_Initialize();
- sineWaveInit();
- while(1)
- {
- /* Creating the sine wave signal by setting each sample */
- DAC0_SetOutput(sineWave[sineIndex++]);
- sineIndex = sineIndex % SINE_PERIOD_STEPS;
- _delay_us(STEP_DELAY_TIME);
- }
- }
测试例程频率设置是50Hz，实测45Hz，Delay延时不太准，如果改用定时器触发输出，效果应该好很多。
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