360475e266
This adds I2SOut and PDMIn support via PIO. StateMachines can now: * read and read while writing * transfer in 1, 2 or 4 byte increments * init pins based on expected defaults automatically * be stopped and restarted * rxfifo can be cleared and rxstalls detected (good for tracking when the reading code isn't keeping up) Fixes #4162
45 lines
886 B
Python
45 lines
886 B
Python
import audiobusio
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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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def mean(values):
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return sum(values) / len(values)
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def normalized_rms(values):
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minbuf = int(mean(values))
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samples_sum = sum(
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float(sample - minbuf) * (sample - minbuf)
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for sample in values
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)
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return math.sqrt(samples_sum / len(values))
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# signed 16 bit
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s16 = array.array("H", [0] * 10000)
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pdm = audiobusio.PDMIn(clock_pin=board.D11, data_pin=board.D12, sample_rate=24000, bit_depth=16)
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print("starting read")
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trigger.value = False
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count = pdm.record(s16, len(s16))
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trigger.value = True
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print("read done")
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print("recorded {} samples".format(count))
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for v in s16[:count]:
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print(v)
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magnitude = normalized_rms(s16)
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print("magnitude", magnitude)
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print("count", count)
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print("done")
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