Add example demoing fastShiftIn/fastShiftOut

Author: Nathan Seidle

libraries/Examples/examples/Advanced/fastShift/fastShift.ino

@@ -0,0 +1,50 @@
+/* 
+  fastShiftIn() / fastShiftOut()
+  By: Nathan Seidle
+  SparkFun Electronics
+  Date: July 8th, 2019
+  License: This code is public domain.
+
+  SparkFun labored with love to create this code. Feel like supporting open source hardware?
+  Buy a board from SparkFun! https://www.sparkfun.com/products/15376
+
+  This example shows how use the new fastShiftOut/In functions.
+*/
+
+//Can be any GPIO
+#define CLOCK_PIN 14
+#define DATA_PIN 27
+
+void setup()
+{
+  Serial.begin(9600);
+  Serial.println("SparkFun Fast Shiftout Example");
+
+  pinMode(CLOCK_PIN, OUTPUT);
+  pinMode(DATA_PIN, OUTPUT);
+
+  //enableBurstMode(); //Optional. Go to 96MHz. Roughly doubles the speed of shiftOut and fastShiftOut
+
+  //This is the standard shiftOut() method
+//    while (1)
+//    {
+//      shiftOut(DATA_PIN, CLOCK_PIN, LSBFIRST, 0x0F); //Without BurstMode shiftOut runs at ~610kHz
+//    }
+
+  //Example of new fastShiftOut() method
+
+  //Configure the pins that are to be used for Fast GPIO.
+  enableFastShift(DATA_PIN, CLOCK_PIN);
+  while (1)
+  {
+    fastShiftOut(DATA_PIN, CLOCK_PIN, LSBFIRST, 0x0F); //Without BurstMode fastShiftOut runs at 4MHz
+    //byte incoming = fastShiftIn(DATA_PIN, CLOCK_PIN, LSBFIRST); //Without BurstMode fastShiftIn runs at 3.5MHz
+  }
+}
+
+void loop()
+{
+
+}
+
+