| 基本用法 from pyb import DAC dac = DAC(1) # create DAC 1 on pin X5 dac.write(128) # write a value to the DAC (makes X5 1.65V) dac = DAC(1, bits=12) # use 12 bit resoluon dac.write(4095) # output maximum value, 3.3V输出正弦波 import math from pyb import DAC # create a buffer containing a sine-wave buf = bytearray(100) for i in range(len(buf)): buf = 128 + int(127 * math.sin(2 * math.pi * i / len(buf))) # output the sine-wave at 400Hz dac = DAC(1) dac.write_timed(buf, 400 * len(buf), mode=DAC.CIRCULAR)输出12位精度正弦波 import math from array import array from pyb import DAC # create a buffer containing a sine-wave, using half-word samples buf = array('H', 2048 + int(2047 * math.sin(2 * math.pi * i / 128)) for i in range(128)) # output the sine-wave at 400Hz dac = DAC(1, bits=12) dac.write_timed(buf, 400 * len(buf), mode=DAC.CIRCULAR) class pyb.DAC(port, bits=8)定义DAC port，1或2，对应X5（PA4）/X6（PA5） bits，输出精度，可以是8或12 dac.init(bits=8) 初始化DAC dac.noise(freq) 以指定频率，产生伪随机噪声信号 dac.triangle(freq) 以指定频率产生三角波 dac.write(value) 写入参数。在8bits时，参数范围[0-255]；在12bits时，参数范围[0..4095] dac.write_timed(data, freq, *, mode=DAC.NORMAL) 使用DMA方式周期写入数据 data，缓冲区数组 freq，默认使用Timer(6)，用指定频率更新。也可以指定另外的定时器，有效的定时器是[2, 4, 5, 6, 7, 8] mode，DAC.NORMAL or DAC.CIRCULAR |