private void WriteRegister8(byte reg, byte data)
{
outbuf[0] = 0x40;
outbuf[1] = reg;
outbuf[2] = data;
dev.Write(outbuf, 3);
}
/// <summary>
/// Constructor for a chain of one or more SN74HC595 shift registers.
/// </summary>
/// <param name="dev">SPI device object.</param>
/// <param name="stages">Number of stages in the chain.</param>
/// <param name="initialstate">Initial shift register chain state.</param>
public Device(IO.Interfaces.SPI.Device dev, int stages = 1, byte[] initialstate = null)
{
// Validate parameters
if (stages < 1)
{
throw new System.Exception("stages paramter is invalid");
}
if (initialstate != null)
{
if (initialstate.Length != stages)
{
throw new System.Exception("initialstate parameter length is invalid");
}
}
// Save the SPI device object
spidev = dev;
// Allocate shift register state buffer
statebuf = new byte[stages];
// Initialize shift register state buffer
if (initialstate == null)
{
for (int i = 0; i < state.Length; i++)
{
statebuf[i] = 0;
}
}
else
{
statebuf = initialstate;
}
// Shift out initial register state
spidev.Write(statebuf, statebuf.Length);
}
/// <summary>
/// Set a single bit in the shift register chain.
/// </summary>
/// <param name="index">Shift register stage number. Zero indicates
/// the first register stage.</param>
/// <param name="mask">Shift register bit mask.</param>
public void SetBit(int index, byte mask)
{
statebuf[index] |= mask;
spidev.Write(statebuf, statebuf.Length);
}