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