+/* 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 );
+}
+