flutter_gpiod 0.3.0 flutter_gpiod: ^0.3.0 copied to clipboard
Dart package for accessing GPIO using the GPIO character device interface on linux / Android (root required). Supports signal edge listening, active state, open source/drain and (if supported by platf [...]
📰 NEWS #
- If you have root access, works on Android too (See issue #9)
- even though the name seems to imply otherwise, the flutter SDK is not required to use this package.
libgpiod
is no longer required- a lot of the
async
stuff has gone away, making it nicer & easier to use - The package uses FFI with ioctls now, which should result in lower latency. (The event listener isolate gets signal edge events ~300us after they ocurred, the main isolate after ~1000us)
- works without flutter-pi now too
- tested & working on ARM32, but should work on other 32-bit and 64-bit linux platforms too (untested though)
flutter_gpiod #
A dart package for GPIO access on linux / Android (root required) using the linux GPIO character-device interface.
Getting Started #
Then, you can retrieve the list of GPIO chips attached to your system using [FlutterGpiod.chips]. Each chip has a name, label and a number of GPIO lines associated with it.
final chips = FlutterGpiod.instance.chips;
for (final chip in chips) {
print("chip name: ${chip.name}, chip label: ${chip.label}");
for (final line in chip.lines) {
print(" line: $line");
}
}
Each line also has some information associated with it that can be retrieved using [GpioLine.info]. The information can change at any time if the line is not owned/requested by you.
// Get the chip with label 'pinctrl-bcm2835'.
// This is the main Raspberry Pi GPIO chip.
final chip = FlutterGpiod.instance.chips.singleWhere((chip) => chip.label == 'pinctrl-bcm2835');
// Get line 22 of the 'pinctrl-bcm2835' GPIO chip.
// This is the BCM 22 pin of the Raspberry Pi.
final line = chip.lines[22];
print("line info: ${line.info}")
To control a line (to read or write values or to listen for edges), you need to request it using [GpioLine.requestInput] or [GpioLine.requestOutput].
final chip = FlutterGpiod.instance.chips.singleWhere((chip) => chip.label == 'pinctrl-bcm2835');
final line = chip.lines[22];
// request it as input.
line.requestInput();
print("line value: ${line.getValue()}");
line.release();
// now we're requesting it as output.
line.requestOutput(initialValue: true);
line.setValue(false);
line.release();
// request it as input again, but this time we're also listening
// for edges; both in this case.
line.requestInput(triggers: {SignalEdge.falling, SignalEdge.rising});
print("line value: ${line.getValue()}");
// line.onEvent will not emit any events if no triggers
// are requested for the line.
// this will run forever
await for (final event in line.onEvent) {
print("got GPIO line signal event: $event");
}
line.release();