150 lines
5.0 KiB
Python
150 lines
5.0 KiB
Python
import digitalio
|
|
|
|
|
|
def intify_coordinate(row, col):
|
|
return row << 8 | col
|
|
|
|
|
|
class DiodeOrientation:
|
|
'''
|
|
Orientation of diodes on handwired boards. You can think of:
|
|
COLUMNS = vertical
|
|
ROWS = horizontal
|
|
'''
|
|
|
|
COLUMNS = 0
|
|
ROWS = 1
|
|
|
|
|
|
class MatrixScanner:
|
|
def __init__(
|
|
self,
|
|
cols,
|
|
rows,
|
|
diode_orientation=DiodeOrientation.COLUMNS,
|
|
rollover_cols_every_rows=None,
|
|
):
|
|
self.len_cols = len(cols)
|
|
self.len_rows = len(rows)
|
|
|
|
# A pin cannot be both a row and column, detect this by combining the
|
|
# two tuples into a set and validating that the length did not drop
|
|
#
|
|
# repr() hackery is because CircuitPython Pin objects are not hashable
|
|
unique_pins = {repr(c) for c in cols} | {repr(r) for r in rows}
|
|
assert (
|
|
len(unique_pins) == self.len_cols + self.len_rows
|
|
), 'Cannot use a pin as both a column and row'
|
|
del unique_pins
|
|
|
|
self.diode_orientation = diode_orientation
|
|
|
|
# __class__.__name__ is used instead of isinstance as the MCP230xx lib
|
|
# does not use the digitalio.DigitalInOut, but rather a self defined one:
|
|
# https://github.com/adafruit/Adafruit_CircuitPython_MCP230xx/blob/3f04abbd65ba5fa938fcb04b99e92ae48a8c9406/adafruit_mcp230xx/digital_inout.py#L33
|
|
|
|
if self.diode_orientation == DiodeOrientation.COLUMNS:
|
|
self.outputs = [
|
|
x
|
|
if x.__class__.__name__ is 'DigitalInOut'
|
|
else digitalio.DigitalInOut(x)
|
|
for x in cols
|
|
]
|
|
self.inputs = [
|
|
x
|
|
if x.__class__.__name__ is 'DigitalInOut'
|
|
else digitalio.DigitalInOut(x)
|
|
for x in rows
|
|
]
|
|
self.translate_coords = True
|
|
elif self.diode_orientation == DiodeOrientation.ROWS:
|
|
self.outputs = [
|
|
x
|
|
if x.__class__.__name__ is 'DigitalInOut'
|
|
else digitalio.DigitalInOut(x)
|
|
for x in rows
|
|
]
|
|
self.inputs = [
|
|
x
|
|
if x.__class__.__name__ is 'DigitalInOut'
|
|
else digitalio.DigitalInOut(x)
|
|
for x in cols
|
|
]
|
|
self.translate_coords = False
|
|
else:
|
|
raise ValueError(
|
|
'Invalid DiodeOrientation: {}'.format(self.diode_orientation)
|
|
)
|
|
|
|
for pin in self.outputs:
|
|
pin.switch_to_output()
|
|
|
|
for pin in self.inputs:
|
|
pin.switch_to_input(pull=digitalio.Pull.UP)
|
|
|
|
self.rollover_cols_every_rows = rollover_cols_every_rows
|
|
if self.rollover_cols_every_rows is None:
|
|
self.rollover_cols_every_rows = self.len_rows
|
|
|
|
self.len_state_arrays = self.len_cols * self.len_rows
|
|
self.state = bytearray(self.len_state_arrays)
|
|
self.report = bytearray(3)
|
|
|
|
def scan_for_changes(self):
|
|
'''
|
|
Poll the matrix for changes and return either None (if nothing updated)
|
|
or a bytearray (reused in later runs so copy this if you need the raw
|
|
array itself for some crazy reason) consisting of (row, col, pressed)
|
|
which are (int, int, bool)
|
|
'''
|
|
ba_idx = 0
|
|
any_changed = False
|
|
|
|
for oidx, opin in enumerate(self.outputs):
|
|
opin.value = False
|
|
|
|
for iidx, ipin in enumerate(self.inputs):
|
|
# cast to int to avoid
|
|
#
|
|
# >>> xyz = bytearray(3)
|
|
# >>> xyz[2] = True
|
|
# Traceback (most recent call last):
|
|
# File "<stdin>", line 1, in <module>
|
|
# OverflowError: value would overflow a 1 byte buffer
|
|
#
|
|
# I haven't dived too far into what causes this, but it's
|
|
# almost certainly because bool types in Python aren't just
|
|
# aliases to int values, but are proper pseudo-types
|
|
new_val = int(not ipin.value)
|
|
old_val = self.state[ba_idx]
|
|
|
|
if old_val != new_val:
|
|
if self.translate_coords:
|
|
new_oidx = oidx + self.len_cols * (
|
|
iidx // self.rollover_cols_every_rows
|
|
)
|
|
new_iidx = iidx - self.rollover_cols_every_rows * (
|
|
iidx // self.rollover_cols_every_rows
|
|
)
|
|
|
|
self.report[0] = new_iidx
|
|
self.report[1] = new_oidx
|
|
else:
|
|
self.report[0] = oidx
|
|
self.report[1] = iidx
|
|
|
|
self.report[2] = new_val
|
|
self.state[ba_idx] = new_val
|
|
|
|
any_changed = True
|
|
break
|
|
|
|
ba_idx += 1
|
|
|
|
opin.value = True
|
|
if any_changed:
|
|
break
|
|
|
|
if any_changed:
|
|
return self.report
|