GpioLine class

Provides access to a single GPIO line / pin.

Basically has 3 states that define the methods you can call: unrequested, requested input, requested output

Example usage of GpioLine:

import 'package:gpiod/proxy_gpiod.dart';

final gpio = ProxyGpiod.getInstance()

// get the line with index 22 from the first chip
final line = gpio.chips.singleWhere(
  (chip) => chip.label == 'pinctrl-bcm2835'
);
print("pinctrl-bcm2835, line 22: $(await line.info)");

// request is as output and initialize it with false
await line.requestOutput(
  consumer: "flutter_gpiod output test",
  initialValue: false
));

// set the line active
line.setValue(true);

await Future.delayed(Duration(milliseconds: 500));

// set the line inactive again
line.setValue(false);

await line.release();

// request the line as input, and listen for both edges
// we don't use `line.reconfigure` because that doesn't
// allow us to specify triggers.
line.requestInput(
  consumer: "flutter_gpiod input test",
  triggers: const {SignalEdge.rising, SignalEdge.falling}
));

// print line events for eternity
for (final event in line.onEvent) {
  print("gpio line signal event: $event");
}

// line.release();

Notice that access to the methods in GpioLine is synchronized.

This will throw an error:

final gpio = ProxyGpiod.getInstance();

final line = gpio.chips.singleWhere(
  (chip) => chip.label == 'pinctrl-bcm2835'
);

line.requestInput() // notice the missing await

print("is line requested? ${line.requested}"); // this will throw the error.
// The line ownership is undefined until the Future returned by line.requestInput() finishes.
// Because this code doesn't wait until the returned Future completes,
//   the request may still be running when `line.requested` is queried.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

info → LineInfo

Returns the line info for this line.

no setter

onEdge → Stream<SignalEdge>

Broadcast stream of signal edges.

no setter

onEvent → Stream<SignalEvent>

Gets a broadcast stream of SignalEvents for this line.

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

triggers → Set<SignalEdge>

Provides synchronous access to info.

no setter

Methods

getValue() → bool

Reads the value of the line (active / inactive)

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

reconfigureInput({Bias bias = Bias.unknown, ActiveState activeState = ActiveState.high}) → void

Reconfigures the line as input with the given configuration.

reconfigureOutput({OutputMode outputMode = OutputMode.pushPull, Bias bias = Bias.unknown, ActiveState activeState = ActiveState.high, bool initialValue = false}) → void

Reconfigures the line as output with the given configuration.

release() → void

Releases the line, so you don't own it anymore.

requestInput({String? consumer, Bias bias = Bias.unknown, ActiveState activeState = ActiveState.high, Set<SignalEdge> triggers = const {}}) → void

Requests ownership of a GPIO line with the given configuration.

requestOutput({String consumer = '', OutputMode outputMode = OutputMode.pushPull, Bias bias = Bias.unknown, ActiveState activeState = ActiveState.high, bool initialValue = false}) → void

setValue(bool value) → void

Sets the value of the line to active (true) or inactive (false).

toString() → String

A string representation of this object.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited