import audiocore import audiopwmio import board import digitalio import array import time import math trigger = digitalio.DigitalInOut(board.D4) trigger.switch_to_output(True) # Generate one period of sine wav. length = 8000 // 440 samples = [] sample_names = ["unsigned 8 bit", "signed 8 bit", "unsigned 16 bit", "signed 16 bit"] # unsigned 8 bit u8 = array.array("B", [0] * length) for i in range(length): u8[i] = int(math.sin(math.pi * 2 * i / length) * (2**7) + 2**7) samples.append(audiocore.RawSample(u8, sample_rate=4000)) # signed 8 bit s8 = array.array("b", [0] * length) for i in range(length): s8[i] = int(math.sin(math.pi * 2 * i / length) * (2**7)) samples.append(audiocore.RawSample(s8, sample_rate=16000)) # unsigned 16 bit u16 = array.array("H", [0] * length) for i in range(length): u16[i] = int(math.sin(math.pi * 2 * i / length) * (2**15) + 2**15) samples.append(audiocore.RawSample(u16, sample_rate=8000)) # signed 16 bit s16 = array.array("h", [0] * length) for i in range(length): s16[i] = int(math.sin(math.pi * 2 * i / length) * (2**15)) samples.append(audiocore.RawSample(s16, sample_rate=8000)) dac = audiopwmio.PWMAudioOut(board.D13) for sample, name in zip(samples, sample_names): print(name) trigger.value = False dac.play(sample, loop=True) time.sleep(1) dac.stop() time.sleep(0.1) trigger.value = True print() print("done")