--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Scan/FACOM6684/scan_loop.c	Mon Jan 14 21:31:50 2013 -0500
@@ -0,0 +1,276 @@
+/* Copyright (C) 2013 by Jacob Alexander
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+// ----- Includes -----
+
+// AVR Includes
+#include <avr/interrupt.h>
+#include <avr/io.h>
+#include <util/delay.h>
+
+// Project Includes
+#include <led.h>
+#include <print.h>
+
+// Local Includes
+#include "scan_loop.h"
+
+
+
+// ----- Defines -----
+
+// Pinout Defines
+#define HOLD_PORT PORTD
+#define HOLD_DDR   DDRD
+#define HOLD_PIN      3
+
+
+// ----- Macros -----
+
+// Make sure we haven't overflowed the buffer
+#define bufferAdd(byte) \
+		if ( KeyIndex_BufferUsed < KEYBOARD_BUFFER ) \
+			KeyIndex_Buffer[KeyIndex_BufferUsed++] = byte
+
+
+
+// ----- Variables -----
+
+// Buffer used to inform the macro processing module which keys have been detected as pressed
+volatile uint8_t KeyIndex_Buffer[KEYBOARD_BUFFER];
+volatile uint8_t KeyIndex_BufferUsed;
+volatile uint8_t KeyIndex_Add_InputSignal; // Used to pass the (click/input value) to the keyboard for the clicker
+
+
+// Buffer Signals
+volatile uint8_t BufferReadyToClear;
+
+
+
+// ----- Function Declarations -----
+
+void processKeyValue( uint8_t keyValue );
+void  removeKeyValue( uint8_t keyValue );
+
+
+
+// ----- Interrupt Functions -----
+
+// USART Receive Buffer Full Interrupt
+ISR(USART1_RX_vect)
+{
+	cli(); // Disable Interrupts
+
+	uint8_t keyValue = 0x00;
+	uint8_t keyState = 0x00;
+
+	// Read the scancode packet from the USART (1st to 8th bits)
+	keyValue = UDR1;
+
+	// Read the release/press bit (9th bit) XXX Unnecessary, and wrong it seems, parity bit? or something else?
+	keyState = UCSR1B & 0x02;
+
+	// High bit of keyValue, also represents press/release
+	keyState = keyValue & 0x80 ? 0x00 : 0x02;
+
+	// Debug
+	char tmpStr[6];
+	hexToStr( keyValue & 0x7F, tmpStr );
+
+	// Process the scancode
+	switch ( keyState )
+	{
+	case 0x00: // Released
+		dPrintStrs( tmpStr, "R  " ); // Debug
+
+		// Remove key from press buffer
+		removeKeyValue( keyValue & 0x7F );
+		break;
+
+	case 0x02: // Pressed
+		dPrintStrs( tmpStr, "P " ); // Debug
+
+		// New key to process
+		processKeyValue( keyValue & 0x7F );
+		break;
+	}
+
+	sei(); // Re-enable Interrupts
+}
+
+
+
+// ----- Functions -----
+
+// Setup
+inline void scan_setup()
+{
+	// Setup the the USART interface for keyboard data input
+	// NOTE: The input data signal needs to be inverted for the Teensy USART to properly work
+	
+	// Setup baud rate
+	// 16 MHz / ( 16 * Baud ) = UBRR
+	// Baud <- 0.823284 ms per bit, thus 1000 / 0.823284 = 1214.65004 -> 823.2824
+	// Thus baud setting = 823
+	uint16_t baud = 823; // Max setting of 4095
+	UBRR1H = (uint8_t)(baud >> 8);
+	UBRR1L = (uint8_t)baud;
+
+	// Enable the receiver, and RX Complete Interrupt as well as 9 bit data
+	UCSR1B = 0x94;
+
+	// The transmitter is only to be enabled when needed
+	// Set the pin to be pull-up otherwise (use the lowered voltage inverter in order to sink)
+	HOLD_DDR  &= ~(1 << HOLD_PIN);
+	HOLD_PORT |=  (1 << HOLD_PIN);
+
+	// Set frame format: 9 data, 1 stop bit, no parity
+	// Asynchrounous USART mode
+	UCSR1C = 0x06;
+
+	// Initially buffer doesn't need to be cleared (it's empty...)
+	BufferReadyToClear = 0;
+
+	// InputSignal is off by default
+	KeyIndex_Add_InputSignal = 0x00;
+
+	// Reset the keyboard before scanning, we might be in a wierd state
+	scan_resetKeyboard();
+}
+
+
+// Main Detection Loop
+// Not needed for the BETKB, this is just a busy loop
+inline uint8_t scan_loop()
+{
+	return 0;
+}
+
+void processKeyValue( uint8_t keyValue )
+{
+	// Interpret scan code
+	switch ( keyValue )
+	{
+	case 0x00: // Break code from input?
+		break;
+	default:
+		// Make sure the key isn't already in the buffer
+		for ( uint8_t c = 0; c < KeyIndex_BufferUsed + 1; c++ )
+		{
+			// Key isn't in the buffer yet
+			if ( c == KeyIndex_BufferUsed )
+			{
+				bufferAdd( keyValue );
+
+				// Only send data if enabled
+				if ( KeyIndex_Add_InputSignal )
+					scan_sendData( KeyIndex_Add_InputSignal );
+				break;
+			}
+
+			// Key already in the buffer
+			if ( KeyIndex_Buffer[c] == keyValue )
+				break;
+		}
+		break;
+	}
+}
+
+void removeKeyValue( uint8_t keyValue )
+{
+	// Check for the released key, and shift the other keys lower on the buffer
+	uint8_t c;
+	for ( c = 0; c < KeyIndex_BufferUsed; c++ )
+	{
+		// Key to release found
+		if ( KeyIndex_Buffer[c] == keyValue )
+		{
+			// Shift keys from c position
+			for ( uint8_t k = c; k < KeyIndex_BufferUsed - 1; k++ )
+				KeyIndex_Buffer[k] = KeyIndex_Buffer[k + 1];
+
+			// Decrement Buffer
+			KeyIndex_BufferUsed--;
+
+			break;
+		}
+	}
+
+	// Error case (no key to release)
+	if ( c == KeyIndex_BufferUsed + 1 )
+	{
+		errorLED( 1 );
+		char tmpStr[6];
+		hexToStr( keyValue, tmpStr );
+		erro_dPrint( "Could not find key to release: ", tmpStr );
+	}
+}
+
+// Send data 
+uint8_t scan_sendData( uint8_t dataPayload )
+{
+	// Enable the USART Transmitter
+	UCSR1B |=  (1 << 3);
+
+	// Debug
+	char tmpStr[6];
+	hexToStr( dataPayload, tmpStr );
+	info_dPrint( "Sending - ", tmpStr );
+
+	UDR1 = dataPayload;
+
+	// Wait for the payload
+	_delay_us( 800 );
+
+	// Disable the USART Transmitter
+	UCSR1B &= ~(1 << 3);
+
+	return 0;
+}
+
+// Signal KeyIndex_Buffer that it has been properly read
+void scan_finishedWithBuffer( void )
+{
+}
+
+// Signal that the keys have been properly sent over USB
+void scan_finishedWithUSBBuffer( void )
+{
+}
+
+// Reset/Hold keyboard
+// NOTE: Does nothing with the BETKB
+void scan_lockKeyboard( void )
+{
+}
+
+// NOTE: Does nothing with the BETKB
+void scan_unlockKeyboard( void )
+{
+}
+
+// Reset Keyboard
+void scan_resetKeyboard( void )
+{
+	// Not a calculated valued...
+	_delay_ms( 50 );
+}
+