1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
|
#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0-or-later
# SPDX-FileCopyrightText: 2023 Kent Gibson <warthog618@gmail.com>
"""Minimal example of watching for edges on a single line."""
import gpiod
from datetime import timedelta
from gpiod.line import Bias, Edge
def edge_type_str(event):
if event.event_type is event.Type.RISING_EDGE:
return "Rising"
if event.event_type is event.Type.FALLING_EDGE:
return "Falling"
return "Unknown"
def watch_line_value(chip_path, line_offset):
# Assume a button connecting the pin to ground,
# so pull it up and provide some debounce.
with gpiod.request_lines(
chip_path,
consumer="watch-line-value",
config={
line_offset: gpiod.LineSettings(
edge_detection=Edge.BOTH,
bias=Bias.PULL_UP,
debounce_period=timedelta(milliseconds=10),
)
},
) as request:
while True:
# Blocks until at least one event is available
for event in request.read_edge_events():
print(
"line: {} type: {:<7} event #{}".format(
event.line_offset, edge_type_str(event), event.line_seqno
)
)
if __name__ == "__main__":
try:
watch_line_value("/dev/gpiochip0", 5)
except OSError as ex:
print(ex, "\nCustomise the example configuration to suit your situation")
|
