59 lines
2.1 KiB
Python
59 lines
2.1 KiB
Python
import digitalio
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from kmk.common.abstract.matrix_scanner import AbstractMatrixScanner
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from kmk.common.consts import DiodeOrientation
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from kmk.common.event_defs import matrix_changed
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class MatrixScanner(AbstractMatrixScanner):
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def __init__(self, cols, rows, diode_orientation=DiodeOrientation.COLUMNS):
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# A pin cannot be both a row and column, detect this by combining the
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# two tuples into a set and validating that the length did not drop
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#
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# repr() hackery is because CircuitPython Pin objects are not hashable
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unique_pins = {repr(c) for c in cols} | {repr(r) for r in rows}
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if len(unique_pins) != len(cols) + len(rows):
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raise ValueError('Cannot use a pin as both a column and row')
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self.cols = [digitalio.DigitalInOut(pin) for pin in cols]
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self.rows = [digitalio.DigitalInOut(pin) for pin in rows]
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self.diode_orientation = diode_orientation
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self.last_pressed_len = 0
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if self.diode_orientation == DiodeOrientation.COLUMNS:
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self.outputs = self.cols
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self.inputs = self.rows
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elif self.diode_orientation == DiodeOrientation.ROWS:
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self.outputs = self.rows
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self.inputs = self.cols
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else:
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raise ValueError('Invalid DiodeOrientation: {}'.format(
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self.diode_orientation,
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))
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for pin in self.outputs:
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pin.switch_to_output()
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for pin in self.inputs:
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pin.switch_to_input(pull=digitalio.Pull.DOWN)
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def scan_for_pressed(self):
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pressed = []
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for oidx, opin in enumerate(self.outputs):
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opin.value = True
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for iidx, ipin in enumerate(self.inputs):
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if ipin.value:
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pressed.append(
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(oidx, iidx) if self.diode_orientation == DiodeOrientation.ROWS else (iidx, oidx) # noqa
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)
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opin.value = False
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if len(pressed) != self.last_pressed_len:
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self.last_pressed_len = len(pressed)
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return matrix_changed(pressed)
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return None # The default, but for explicitness
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