private void I2CStart()
{
// start signal = pull sda down while scl is high
_sda.On();
I2CSleep();
_scl.On();
I2CSleep();
_sda.Off();
I2CSleep();
_scl.Off();
I2CSleep();
}
/// <summary>
/// Create a shift register with the appropriate Pi pins
/// </summary>
/// <param name="signalPin">GPIO Pin connected to Pin 14 of the SN74HC595N</param>
/// <param name="signalClockPin">GPIO Pin connected to Pin 11 of the SN74HC595N</param>
/// <param name="registerClockPin">GPIO Pin connected to Pin 12 of the SN74HC595N</param>
/// <param name="clearPin">GPIO Pin connected to Pin 10 of the SN74HC595N</param>
/// <param name="outputEnabledPin">GPIO Pin connected to Pin 13 of the SN74HC595N</param>
/// <param name="numChips">The number of SN74HC595N connected in series.</param>
/// To connect multiple chips in series connect
/// Pi Chip 1 Chip 2 Chip 3
/// signalPin -> Pin 14
/// signalClockPin -> Pin 11 -> Pin 11 -> Pin 11
/// registerClockPin -> Pin 12 -> Pin 12 -> Pin 12
/// clearPin -> Pin 10 -> Pin 10 -> Pin 10
/// outputEnabledPin -> Pin 13 -> Pin 13 -> Pin 13
/// Pin 9 -> Pin 14
/// Pin 9 -> Pin 14
public ShiftRegister(PreparedPin signalPin, PreparedPin signalClockPin, PreparedPin registerClockPin, PreparedPin clearPin, PreparedPin outputEnabledPin,
int numChips = 1)
{
_signalPin = signalPin;
_signalClockPin = signalClockPin;
_registerClockPin = registerClockPin;
clearPin.On(); // make sure the clear pin is pulled high
_outputEnabledPin = outputEnabledPin;
_values = new bool[numChips * 8];
SendAllValues();
}
/// <summary>
/// This is the bit that actually does the bit banging to the chip
/// </summary>
private void SendAllValues()
{
_registerClockPin.Off();
foreach (var b in _values.Reverse())
{
_signalClockPin.Off();
if (b)
{
_signalPin.On();
}
else
{
_signalPin.Off();
}
_signalClockPin.On();
}
_registerClockPin.On();
_registerClockPin.Off();
_outputEnabledPin.Off(); // low = enabled, ensure that the output is actually enabled
}
