/// <summary>
/// Sets the state of the specified pin.
/// </summary>
/// <param name="pin">
/// The pin to alter.
/// </param>
/// <param name="state">
/// The state of the pin to set.
/// </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="pin"/> cannot be null.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// This instance has been disposed and can no longer be used.
/// </exception>
/// <exception cref="ArgumentException">
/// The specified pin does not exist in the pin cache.
/// </exception>
/// <exception cref="System.IO.IOException">
/// Failed to write the new state to the device.
/// </exception>
public void SetPinState(IPCF8574Pin pin, PinState state)
{
if (pin == null)
{
throw new ArgumentNullException("pin");
}
if (this._isDisposed)
{
throw new ObjectDisposedException("CyrusBuilt.MonoPi.IO.PCF.PCF8574GpioProvider");
}
if (!this._pinCache.Contains(pin))
{
throw new ArgumentException("Cannot set the state of a pin that does not exist in the pin cache.", "pin");
}
// We only do this if the state is actually changing.
PinState cstate = this._pinCache[this._pinCache.IndexOf(pin)].State;
if (cstate != state)
{
Byte stateVal = this._currentStates.Empty ? (Byte)0 : this._currentStates.ToByteArray()[0];
this._currentStates.Set(pin.Address, (state == PinState.High));
this._device.WriteByte(this._busAddress, stateVal);
this.OnPinStateChanged(new PinStateChangeEventArgs(pin.Address, cstate, state));
}
}
/// <summary>
/// Polls all the pins on the PCF8574 every ~50ms and refreshes their states.
/// This will fire a state change event for any and all pins that have changed
/// state since the last check. This will also fire a failure event if any
/// exceptions are thrown.
/// </summary>
private void ExecutePoll()
{
while (!this._pollAbort)
{
try {
// Read device pin states.
Byte[] buffer = this._device.ReadBytes(this._busAddress, 1);
BitSet pinStates = BitSet.ValueOf(buffer);
// Determine if there is a pin state difference.
IPCF8574Pin pin = null;
PinState newState = PinState.Low;
PinState oldState = PinState.Low;
for (Int32 index = 0; index < pinStates.Size; index++)
{
if (pinStates.Get(index) != this._currentStates.Get(index))
{
pin = PCF8574Pin.ALL[index];
// Is the state actually changing?
newState = pinStates.Get(index) ? PinState.High : PinState.Low;
oldState = this._pinCache[this._pinCache.IndexOf(pin)].State;
if (newState != oldState)
{
// Cache the new state.
this._pinCache[this._pinCache.IndexOf(pin)].SetState(newState);
this._currentStates.Set(index, pinStates.Get(index));
// Only dispatch events for input pins.
if (this.GetPinMode(pin) == PinMode.IN)
{
this.OnPinStateChanged(new PinStateChangeEventArgs(pin.Address, oldState, newState));
}
}
}
}
Thread.Sleep(50);
}
catch (Exception ex) {
// If we failed (likely due to an I/O error), then
// fire the failure event and gracefully abort the
// the poll thread.
this.OnPinPollFailed(new PinPollFailEventArgs(ex));
lock (_syncLock) {
this._pollAbort = true;
}
}
}
}
/// <summary>
/// Gets the current state of the specified pin in the pin cache.
/// </summary>
/// <param name="pin">
/// The pin to get the state from.
/// </param>
/// <returns>
/// The state of the pin.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="pin"/> cannot be null.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// This instance has been disposed and can no longer be used.
/// </exception>
/// <exception cref="ArgumentException">
/// The specified pin does not exist in the pin cache.
/// </exception>
public PinState GetPinState(IPCF8574Pin pin)
{
if (pin == null)
{
throw new ArgumentNullException("pin");
}
if (this._isDisposed)
{
throw new ObjectDisposedException("CyrusBuilt.MonoPi.IO.PCF.PCF8574GpioProvider");
}
if (!this._pinCache.Contains(pin))
{
throw new ArgumentException("The specified pin does not exist in the pin cache.", "pin");
}
return(this._pinCache[this._pinCache.IndexOf(pin)].State);
}
/// <summary>
/// Sets the mode of the specified pin.
/// </summary>
/// <param name="pin">
/// The pin to alter.
/// </param>
/// <param name="mode">
/// The mode to set.
/// </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="pin"/> cannot be null.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// This instance has been disposed and can no longer be used.
/// </exception>
/// <exception cref="ArgumentException">
/// The specified pin does not exist in the pin cache.
/// </exception>
public void SetPinMode(IPCF8574Pin pin, PinMode mode)
{
if (pin == null)
{
throw new ArgumentNullException("pin");
}
if (this._isDisposed)
{
throw new ObjectDisposedException("CyrusBuilt.MonoPi.IO.PCF.PCF8574GpioProvider");
}
if (!this._pinCache.Contains(pin))
{
throw new ArgumentException("Cannot set the mode of a pin that does not exist in the pin cache.", "pin");
}
this._pinCache[this._pinCache.IndexOf(pin)].SetMode(mode);
}
/// <summary>
/// Gets the current state of the specified pin in the pin cache.
/// </summary>
/// <param name="pin">
/// The pin to get the state from.
/// </param>
/// <returns>
/// The state of the pin.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="pin"/> cannot be null.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// This instance has been disposed and can no longer be used.
/// </exception>
/// <exception cref="ArgumentException">
/// The specified pin does not exist in the pin cache.
/// </exception>
public PinState GetPinState(IPCF8574Pin pin) {
if (pin == null) {
throw new ArgumentNullException("pin");
}
if (this._isDisposed) {
throw new ObjectDisposedException("CyrusBuilt.MonoPi.IO.PCF.PCF8574GpioProvider");
}
if (!this._pinCache.Contains(pin)) {
throw new ArgumentException("The specified pin does not exist in the pin cache.", "pin");
}
return this._pinCache[this._pinCache.IndexOf(pin)].State;
}
/// <summary>
/// Sets the state of the specified pin.
/// </summary>
/// <param name="pin">
/// The pin to alter.
/// </param>
/// <param name="state">
/// The state of the pin to set.
/// </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="pin"/> cannot be null.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// This instance has been disposed and can no longer be used.
/// </exception>
/// <exception cref="ArgumentException">
/// The specified pin does not exist in the pin cache.
/// </exception>
/// <exception cref="System.IO.IOException">
/// Failed to write the new state to the device.
/// </exception>
public void SetPinState(IPCF8574Pin pin, PinState state) {
if (pin == null) {
throw new ArgumentNullException("pin");
}
if (this._isDisposed) {
throw new ObjectDisposedException("CyrusBuilt.MonoPi.IO.PCF.PCF8574GpioProvider");
}
if (!this._pinCache.Contains(pin)) {
throw new ArgumentException("Cannot set the state of a pin that does not exist in the pin cache.", "pin");
}
// We only do this if the state is actually changing.
PinState cstate = this._pinCache[this._pinCache.IndexOf(pin)].State;
if (cstate != state) {
Byte stateVal = this._currentStates.Empty ? (Byte)0 : this._currentStates.ToByteArray()[0];
this._currentStates.Set(pin.Address, (state == PinState.High));
this._device.WriteByte(this._busAddress, stateVal);
this.OnPinStateChanged(new PinStateChangeEventArgs(pin.Address, cstate, state));
}
}
/// <summary>
/// Sets the mode of the specified pin.
/// </summary>
/// <param name="pin">
/// The pin to alter.
/// </param>
/// <param name="mode">
/// The mode to set.
/// </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="pin"/> cannot be null.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// This instance has been disposed and can no longer be used.
/// </exception>
/// <exception cref="ArgumentException">
/// The specified pin does not exist in the pin cache.
/// </exception>
public void SetPinMode(IPCF8574Pin pin, PinMode mode) {
if (pin == null) {
throw new ArgumentNullException("pin");
}
if (this._isDisposed) {
throw new ObjectDisposedException("CyrusBuilt.MonoPi.IO.PCF.PCF8574GpioProvider");
}
if (!this._pinCache.Contains(pin)) {
throw new ArgumentException("Cannot set the mode of a pin that does not exist in the pin cache.", "pin");
}
this._pinCache[this._pinCache.IndexOf(pin)].SetMode(mode);
}
