/// <summary> Configures the internal resistor for the given pin. </summary>
/// <param name="Pin"> THe pin to configure. </param>
/// <param name="ResMode"> The resistor to apply. </param>
internal static void SetResistor(int Pin, ResistorState ResMode)
{
if (!Initialized)
{
throw new InvalidOperationException("Cannot perform GPIO operations until the system is initialized. Call RasperryPi.Initialize().");
}
int ResistorVal = 0;
if (ResMode == ResistorState.PULL_UP)
{
ResistorVal = 2;
}
else if (ResMode == ResistorState.PULL_DOWN)
{
ResistorVal = 1;
}
External.SetResistor(Pin, ResistorVal);
}
/// <summary> Creates a 8-bit pin mode from the specified parameters. </summary>
internal static byte GetPinMode(bool FastSlew, bool EnableReceiver, ResistorState Resistor, byte ModeID)
{
// Bit | Function | Modes
// ====|====================|=====================
// 0 | Reserved | 0
// 0 | Slew Rate | 0=Fast, 1=Slow
// 0 | Receiver Enable | 0=Disable, 1=Enable
// 0 | Resistor Selection | 0=Pulldown, 1=Pullup
// ----|--------------------|---------------------
// 0 | Resistor Enable | 0=Enable, 1=Disable
// 000 | Mux Select | Value, 0 through 7
// -----------------------------------------------
// Source: AM3359 Technical Reference Manual: http://www.ti.com/product/AM3359/technicaldocuments
// Version P, Page 1512, Section 9.3.1.50, Table 9-60
// Find by searching "conf_<module>" in other versions.
byte Output = 0b0000_0000;
if (!FastSlew)
{
Output |= 0b0100_0000;
}
if (EnableReceiver)
{
Output |= 0b0010_0000;
}
if (Resistor == ResistorState.PULL_UP)
{
Output |= 0b0001_0000;
}
else if (Resistor == ResistorState.NONE)
{
Output |= 0b0000_1000;
}
if (ModeID >= 0b000 && ModeID <= 0b111)
{
Output |= ModeID;
}
return(Output);
}
/// <summary> Resistor state cannot be changed during runtime on BBB, it must be set in the device tree overlay. This will throw an exception. </summary>
public void SetResistor(ResistorState Resistor)
{
throw new NotImplementedException("Resistor state cannot be changed on BBB without re-applying device tree overlay.");
}
/// <summary>
/// Sets the input to either have a ~50KΩ pullup resistor, pulldown resistor, or no resistor.
/// </summary>
public void SetResistor(ResistorState Resistor)
{
RaspberryPi.SetResistor(this.PinNumber, Resistor);
}
public void SetResistor(ResistorState Resistor)
{
throw new InvalidOperationException("PCA9535E does not have configurable input resistors.");
}
public void SetResistor(ResistorState Resistor) => this.Input.SetResistor(Resistor);