Added basic FakeKeyboard sketch (untested!)

FakeKeyboard.pde

@@ -0,0 +1,114 @@
+/**
+ * FakeKeyboard
+ *
+ * Copyright 2009 Jonathan Oxer <jon@oxer.com.au>
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3.
+ *
+ * Enumerates itself as a HID (Human Interface Device) to a host
+ * computer using a USB shield. The Arduino then appears to the host to
+ * be a keyboard and keypress events can be sent on demand.
+ *
+ * This example watches the state of 4 push buttons and when a button
+ * is pressed it sends a matching keypress event to the host.
+ *
+ * http://www.practicalarduino.com/projects/easy/fake-keyboard-and-mouse
+ *
+ * UsbKeyboard.sendKeyStroke(KEY_B, MOD_GUI_LEFT);
+ */
+
+// Requires the use of the "UsbKeyboard" library available from
+//   http://code.rancidbacon.com/ProjectLogArduinoUSB
+#include "UsbKeyboard.h"
+
+// Define the inputs to use for buttons
+#define BUTTON1 9
+#define BUTTON2 10
+#define BUTTON3 11
+#define BUTTON4 12
+
+// Use the on-board LED as an activity display
+int ledPin = 13;
+
+/**
+ * Configure button inputs and set up the USB connection to the host
+ */
+void setup()
+{
+  // Set up the activity display LED
+  pinMode (ledPin, OUTPUT);
+  digitalWrite (ledPin, HIGH);
+
+  // Set the button pins to inputs
+  pinMode (BUTTON1, INPUT);
+  pinMode (BUTTON2, INPUT);
+  pinMode (BUTTON3, INPUT);
+  pinMode (BUTTON4, INPUT);
+
+  // Enable the CPU's internal 20k pull-up resistors on the button
+  // inputs so they default to a "high" state
+  digitalWrite (BUTTON1, HIGH);
+  digitalWrite (BUTTON2, HIGH);
+  digitalWrite (BUTTON3, HIGH);
+  digitalWrite (BUTTON4, HIGH);
+
+  // Disable timer0 since it can mess with the USB timing. Note that
+  // this means some functions such as delay() will no longer work.
+  TIMSK0&=!(1<<TOIE0);
+
+  // Clear interrupts while performing time-critical operations
+  cli();
+
+  // Force re-enumeration so the host will detect us
+  usbDeviceDisconnect();
+  delayMs(250);
+  usbDeviceConnect();
+
+  // Set interrupts again
+  sei();
+}
+
+
+/**
+ * Main program loop. Scan for keypresses and send a matching keypress
+ * event to the host
+ * FIXME: currently repeats as fast as it can. Add transition detection
+ */
+void loop()
+{
+  UsbKeyboard.update();
+
+  if (digitalRead(BUTTON1) == LOW) {
+    UsbKeyboard.sendKeyStroke(KEY_L);
+    // Toggle the status LED
+    digitalWrite(ledPin, !digitalRead(ledPin));
+    digitalWrite(ledPin, !digitalRead(ledPin)); // Toggle status LED
+  }
+
+  if (digitalRead(BUTTON2) == LOW) {
+    UsbKeyboard.sendKeyStroke(KEY_S);
+    digitalWrite(ledPin, !digitalRead(ledPin)); // Toggle status LED
+  }
+
+  if (digitalRead(BUTTON3) == LOW) {
+    UsbKeyboard.sendKeyStroke(KEY_ENTER);
+    digitalWrite(ledPin, !digitalRead(ledPin)); // Toggle status LED
+  }
+
+  if (digitalRead(BUTTON4) == LOW) {
+    UsbKeyboard.sendKeyStroke(KEY_SPACE);
+    digitalWrite(ledPin, !digitalRead(ledPin)); // Toggle status LED
+  }
+}
+
+
+/**
+ * Define our own delay function so that we don't have to rely on
+ * operation of timer0, the interrupt used by the internal delay()
+ */
+void delayMs(unsigned int ms)
+{
+  for (int i = 0; i < ms; i++) {
+    delayMicroseconds(1000);
+  }
+}