I bought my shift register here: http://www.sparkfun.com/products/733 bu there are many different places to shop, so buy it from your favorite place.
Code:
public class ShiftRegister
{
private SPI _dataPort;
private byte[] bitsStorage;
public ShiftRegister(Cpu.Pin latch = Pins.GPIO_PIN_D10)
{
SPI.Configuration spiConfig = new SPI.Configuration(
latch,
false, // active state
0, // setup time
0, // hold time
false, // clock idle state
true, // clock edge
1000, // clock rate
SPI.SPI_module.SPI1);
_dataPort = new SPI(spiConfig);
}
public void WriteByteArray(byte[] byteArray)
{
_dataPort.Write(byteArray);
}
public void StoreBits(string eightBits)
{
if (bitsStorage == null)
bitsStorage = new byte[1]; // Start the storage
else
{
byte[] temp = bitsStorage; // save it temporarily
bitsStorage = new byte[bitsStorage.Length + 1]; // make room for another eight bits
for (int i = 0; i < temp.Length; i++)
bitsStorage[i] = temp[i];
}
while (eightBits.Length < 8)
eightBits = "0" + eightBits;
byte data = 0x00;
char[] chars = eightBits.Substring(0, 8).ToCharArray();
for (int i = 0; i < 8; i++)
data += (byte)((chars[System.Math.Abs(i - 7)] == '1') ? System.Math.Pow(2, i) : 0);
bitsStorage[bitsStorage.Length-1] = data;
}
public void SendBits(bool eraseAfterSend = true)
{
WriteByteArray(bitsStorage); // send sotred bits
if (eraseAfterSend)
bitsStorage = null; // erase all the stored bits if told to.
}
}
The new and improved bit writting system is now designed to work with multiple shift registers. Although it is nice for me because I like binary and stuff... its not the way to go if you're looking for speed. Its best to use the WriteByteArray(byte[] byteArray) method instead.
If you don't have the time or brain power (like me
) to memorize/learn bits to bytes to hex char and all that mess then use this: http://home2.paulsch...et/tools/xlate/All off and on example:
ShiftRegister shifty = new ShiftRegister();
byte[] allOn = new byte[]{0xff, 0xff}; // two bytes because we got two shift registers
byte[] allOff = new byte[]{0x00, 0x00};
while (true)
{
shifty.WriteByteArray(allOn);
Thread.Sleep(1000);
shifty.WriteByteArray(allOff);
Thread.Sleep(1000);
}
Single Shift register:
Shiftregister.png 177.05KB
443 downloadsDouble shift register all the way across the breadboard (I hope you got that reference):
doubleshiftregister.PNG 175.4KB
371 downloadsNote that there are no LEDs or other outputs on that schematic, I just wanted to keep things as neat as possible.
To make it a little more clear (hopefully):
Netduino | SR 1 | SR2
---------------------
GND | 13 | 13
GND | 8 | 8
3V3 | 16 | 16
3V3 | 10 | 10
10 | 12 | 12
13 | 11 | 11
14 | 14 | X
X | 9 | 14
Datasheet for the shift register I am using: http://www.sparkfun....C/SN74HC595.pdf
. You can replace it with a 0, but the method I made will treat everything as 0 if it isn't 1.
