/// <summary>
/// Set up the MCP23S17 for the PiFace Digital board.
/// </summary>
private void InitPiFace()
{
this.InputPins = new PiFaceInputPin[8];
for (int pinNo = 0; pinNo < 8; pinNo++)
{
this.InputPins[pinNo] = new PiFaceInputPin(pinNo);
}
this.OutputPins = new PiFaceOutputPin[8];
for (int pinNo = 0; pinNo < 8; pinNo++)
{
this.OutputPins[pinNo] = new PiFaceOutputPin(pinNo);
}
if (this.spiConnection == null)
{
SpiConnectionSettings spiSettings = new SpiConnectionSettings {
BitsPerWord = 8, Delay = 1, MaxSpeed = 5000000, Mode = SpiMode.Mode0
};
this.spiConnection = new NativeSpiConnection(this.driverName, spiSettings);
}
this.Write(Mcp23S17Register.Iocon, IoconSeqop);
this.SetAllOutputPins(0);
// initialize output and input pins
this.Write(Mcp23S17Register.Iodira, AllPinsOutput);
this.Write(Mcp23S17Register.Iodirb, AllPinsInput);
// set resistor on all input pins to pull up
this.Write(Mcp23S17Register.Gppub, 0xFF);
// set outputs
this.UpdatePiFaceOutputPins();
// Create re-usable buffer for polling input pins
this.CreateReusableBufferForInputPolling();
// Get the initial software input pin state and compare to actual inputs
this.cachedInputState = PiFacePin.AllPinState(this.InputPins);
this.PollInputPins();
}
/// <summary>
/// Update PiFace board with the current vales of the software output pins.
/// </summary>
public void UpdatePiFaceOutputPins()
{
this.Write(Mcp23S17Register.Gpioa, PiFacePin.AllPinState(this.OutputPins));
}
