Commit initial Arduino keyboard sketch. At the moment, this just periodically sends an

arduino_sketch/arduino_sketch.ino

+#include <Wire.h>
+
+#define INTERRUPT_PIN   9
+#define I2C_ADDRESS     0x42
+
+unsigned long next_send_intr;
+int current_intr_val;
+
+void i2cReceive(int bytes) {
+  Serial.print("Bytes available:  ");
+  Serial.println(bytes);
+  
+  while (1 < Wire.available()) { // loop through all but the last
+    char c = Wire.read(); // receive byte as a character
+    Serial.print(c);         // print the character
+  }
+  int x = Wire.read();    // receive byte as an integer
+  Serial.println(x);         // print the integer
+}
+
+void setup() {
+  // Initialize console
+  Serial.begin(9600);
+  Serial.println("Arduino I2C Keyboard Driver Built " __DATE__ " " __TIME__);
+  
+  // Initialize Interrupt Pin
+  digitalWrite(INTERRUPT_PIN, 1);
+  pinMode(INTERRUPT_PIN, OUTPUT);
+
+  // Initialize I2C Slave Interface
+  Wire.begin(I2C_ADDRESS);                // join i2c bus with address #8
+  Wire.onReceive(i2cReceive);
+
+  next_send_intr = 0;
+  current_intr_val = 1;
+}
+
+void loop() {
+  // put your main code here, to run repeatedly:
+  if (millis() > next_send_intr) {
+    current_intr_val = current_intr_val ? 0 : 1;
+    digitalWrite(INTERRUPT_PIN, current_intr_val);
+    next_send_intr = millis() + 5000;
+    Serial.print("Interupt pin now ");
+    Serial.println(current_intr_val);
+  }
+  delay(10);
+}
+
+