+/* Copyright (C) 2012 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 RESET_PORT PORTB
+#define RESET_DDR DDRD
+#define RESET_PIN 0
+
+
+// ----- 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;
+
+
+// Buffer Signals
+volatile uint8_t BufferReadyToClear;
+
+
+
+// ----- Function Declarations -----
+
+void processKeyValue( uint8_t keyValue );
+
+
+
+// ----- Interrupt Functions -----
+
+// USART Receive Buffer Full Interrupt
+ISR(USART1_RX_vect)
+{
+ cli(); // Disable Interrupts
+
+ uint8_t keyValue = 0x00;
+
+ // The interrupt is always for the first item of the packet set, reset the buffer
+ KeyIndex_BufferUsed = 0;
+
+ // Only the first 7 bits have scancode data
+ // The last packet of the packet set has the 8th bit high, all the others are low
+ //
+ // Interrupts are too slow for the rest of the packet set, poll for the rest
+ while ( 1 )
+ {
+ // Read the raw packet from the USART
+ keyValue = UDR1;
+
+ // Debug
+ char tmpStr[6];
+ hexToStr( keyValue, tmpStr );
+ dPrintStrs( tmpStr, " " );
+
+ // Process the scancode
+ processKeyValue( keyValue );
+
+ // Last packet of the set
+ if ( keyValue & 0x80 )
+ {
+ dPrintStrs( "**" );
+ break;
+ }
+
+ // Delay enough so we don't run into the same packet (or the previous buffered packet)
+ _delay_us(10000);
+ }
+
+ 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, transitter, and RX Complete Interrupt as well as 9 bit data
+ UCSR1B = 0x9C;
+
+ // 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;
+
+ // 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;
+}
+
+// TODO
+void processKeyValue( uint8_t keyValue )
+{
+ // Finalize output buffer
+ // Mask 8th bit
+ keyValue &= 0x7F;
+
+ // Interpret scan code
+ switch ( keyValue )
+ {
+ case 0x40: // Clear buffer command
+ info_print("CLEAR!");
+
+ BufferReadyToClear = 1;
+ break;
+ case 0x7F:
+ scan_lockKeyboard();
+ _delay_ms(3000);
+ scan_unlockKeyboard();
+
+ 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 );
+ break;
+ }
+
+ // Key already in the buffer
+ if ( KeyIndex_Buffer[c] == keyValue )
+ break;
+ }
+ break;
+ }
+}
+
+// Send data
+uint8_t scan_sendData( uint8_t dataPayload )
+{
+ UDR1 = dataPayload;
+ return 0;
+}
+
+// Signal KeyIndex_Buffer that it has been properly read
+// TODO
+void scan_finishedWithBuffer( void )
+{
+ return;
+}
+
+// Signal that the keys have been properly sent over USB
+// TODO
+void scan_finishedWithUSBBuffer( void )
+{
+ /*
+ uint8_t foundModifiers = 0;
+
+ // Look for all of the modifiers present, there is a max of 8 (but only keys for 5 on the HASCI version)
+ for ( uint8_t c = 0; c < KeyIndex_BufferUsed; c++ )
+ {
+ // The modifier range is from 0x80 to 0x8F (well, the last bit is the ON/OFF signal, but whatever...)
+ if ( KeyIndex_Buffer[c] <= 0x8F && KeyIndex_Buffer[c] >= 0x80 )
+ {
+ // Add the modifier back into the the Key Buffer
+ KeyIndex_Buffer[foundModifiers] = KeyIndex_Buffer[c];
+ foundModifiers++;
+ }
+ }
+
+ // Adjust the size of the new Key Buffer
+ KeyIndex_BufferUsed = foundModifiers;
+ */
+}
+
+// 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
+// TODO?
+// - Holds the input read line high to flush the buffer
+// - This does not actually reset the keyboard, but always seems brings it to a sane state
+// - Won't work fully if keys are being pressed done at the same time
+void scan_resetKeyboard( void )
+{
+ // Initiate data request line, but don't read the incoming data
+ //REQUEST_DATA(); TODO
+
+ // Not a calculated valued...
+ _delay_ms( 50 );
+
+ // Stop request line
+ //STOP_DATA(); TODO
+}
+