/// <summary>
/// Allocates the specified pin.
/// </summary>
/// <param name="pin">The pin.</param>
/// <param name="direction">The direction.</param>
public void Allocate(ProcessorPin pin, PinDirection direction)
{
var gpioId = string.Format("gpio{0}", (int)pin);
if (Directory.Exists(Path.Combine(gpioPath, gpioId)))
{
HelperFileStream.SaveToFile(Path.Combine(gpioPath, "unexport"), (int)pin);
}
// Export pin for file mode
HelperFileStream.SaveToFile(Path.Combine(gpioPath, "export"), (int)pin);
// Set the direction on the pin and update the exported list
SetPinMode(pin, direction == PinDirection.Input ? Interop.BCM2835_GPIO_FSEL_INPT : Interop.BCM2835_GPIO_FSEL_OUTP);
// Set direction in pin virtual file
var filePath = Path.Combine(gpioId, "direction");
HelperFileStream.SaveToFile(Path.Combine(gpioPath, filePath), direction == PinDirection.Input ? "in" : "out");
if (direction == PinDirection.Input)
{
PinResistor pinResistor;
if (!pinResistors.TryGetValue(pin, out pinResistor) || pinResistor != PinResistor.None)
{
SetPinResistor(pin, PinResistor.None);
}
SetPinDetectedEdges(pin, PinDetectedEdges.Both);
InitializePoll(pin);
}
}
/// <summary>
/// Releases the specified pin.
/// </summary>
/// <param name="pin">The pin.</param>
public void Release(ProcessorPin pin)
{
UninitializePoll(pin);
HelperFileStream.SaveToFile(Path.Combine(gpioPath, "unexport"), (int)pin);
SetPinMode(pin, Interop.BCM2835_GPIO_FSEL_INPT);
}
/// <summary>
/// Allocates the specified pin.
/// </summary>
/// <param name="pin">The pin.</param>
/// <param name="direction">The direction.</param>
public void Allocate(ProcessorPin pin, PinDirection direction)
{
Release(pin);
HelperFileStream.SaveToFile(Path.Combine(gpioPath, "export"), (int)pin);
if (!gpioPathList.ContainsKey(pin))
{
var gpio = new FileGpioHandle {
GpioPath = GuessGpioPath(pin)
};
gpioPathList.Add(pin, gpio);
}
var filePath = Path.Combine(gpioPathList[pin].GpioPath, "direction");
try {
SetPinDirection(filePath, direction);
}
catch (UnauthorizedAccessException) {
// program hasn't been started as root, give it a second to correct file permissions
Thread.Sleep(TimeSpan.FromSeconds(1));
SetPinDirection(filePath, direction);
}
gpioPathList[pin].GpioStream = new FileStream(Path.Combine(GuessGpioPath(pin), "value"), FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
}
/// <summary>
/// Releases the specified pin.
/// </summary>
/// <param name="pin">The pin.</param>
public void Release(ProcessorPin pin)
{
if (gpioPathList.ContainsKey(pin) && gpioPathList[pin].GpioStream != null)
{
gpioPathList[pin].GpioStream.Flush();
gpioPathList[pin].GpioStream = null;
}
if (Directory.Exists(GuessGpioPath(pin)))
{
HelperFileStream.SaveToFile(Path.Combine(gpioPath, "unexport"), (int)pin);
}
}
/// <summary>
/// Sets the detected edges on an input pin.
/// </summary>
/// <param name="pin">The pin.</param>
/// <param name="edges">The edges.</param>
/// <remarks>By default, both edges may be detected on input pins.</remarks>
public void SetPinDetectedEdges(ProcessorPin pin, PinDetectedEdges edges)
{
var edgePath = Path.Combine(gpioPath, string.Format("gpio{0}/edge", (int)pin));
HelperFileStream.SaveToFile(edgePath, ToString(edges));
}
private static void SetPinDirection(string fullFilePath, PinDirection direction)
{
HelperFileStream.SaveToFile(fullFilePath, direction == PinDirection.Input
? "in"
: "out");
}