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controller/Scan/HP150/scan_loop.c
Jacob Alexander 14158009b2 Preparing for Teensy 3 (ARM) integration, abstracting code hierarchy
- Abstracted USB Module
- Abstracted compiler specific includes for Scan, Macro, Debug, and USB modules
- Updated CMake build files to support changes
- Added abstractions necessary to main.c as well as a compiler specific include file
2013-01-26 15:05:28 -05:00

318 lines
8.2 KiB
C

/* 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 -----
// Compiler Includes
#include <Lib/ScanLib.h>
// Project Includes
#include <led.h>
#include <print.h>
// Local Includes
#include "scan_loop.h"
// ----- Defines -----
// Pinout Defines
#define DATA_PORT PORTC
#define DATA_DDR DDRC
#define DATA_PIN 7
#define DATA_OUT PINC
#define CLOCK_PORT PORTC
#define CLOCK_DDR DDRC
#define CLOCK_PIN 6
#define RESET_PORT PORTF
#define RESET_DDR DDRF
#define RESET_PIN 7
// ----- 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
volatile uint8_t currentWaveState = 0;
volatile uint8_t positionCounter = 0;
volatile uint8_t statePositionCounter = 0;
volatile uint16_t stateSamplesTotal = 0;
volatile uint16_t stateSamples = 0;
// Buffer Signals
volatile uint8_t BufferReadyToClear;
// ----- Function Declarations -----
void processKeyValue( uint8_t keyValue );
void removeKeyValue( uint8_t keyValue );
// ----- Interrupt Functions -----
// Generates a constant external clock
ISR( TIMER1_COMPA_vect )
{
if ( currentWaveState )
{
CLOCK_PORT &= ~(1 << CLOCK_PIN);
currentWaveState--; // Keeps track of the clock value (for direct clock output)
statePositionCounter = positionCounter;
positionCounter++; // Counts the number of falling edges, reset is done by the controlling section (reset, or main scan)
}
else
{
CLOCK_PORT |= (1 << CLOCK_PIN);
currentWaveState++;
}
}
// ----- Functions -----
// Setup
inline void scan_setup()
{
// Setup Timer Pulse (16 bit)
// TODO Clock can be adjusted to whatever (read chip datasheets for limits)
// This seems like a good scan speed, as there don't seem to be any periodic
// de-synchronization events, and is fast enough for scanning keys
// Anything much more (100k baud), tends to cause a lot of de-synchronization
// 16 MHz / (2 * Prescaler * (1 + OCR1A)) = 10k baud
// Prescaler is 1
cli();
TCCR1B = 0x09;
OCR1AH = 0x03;
OCR1AL = 0x1F;
TIMSK1 = (1 << OCIE1A);
CLOCK_DDR |= (1 << CLOCK_PIN); // Set the clock pin as an output
DATA_PORT |= (1 << DATA_PIN); // Pull-up resistor for input the data line
sei();
// 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
// Since this function is non-interruptable, we can do checks here on what stage of the
// output clock we are at (0 or 1)
// We are looking for a start of packet
// If detected, all subsequent bits are then logged into a variable
// Once the end of the packet has been detected (always the same length), decode the pressed keys
inline uint8_t scan_loop()
{
// Only use as a valid signal
// Check if there was a position change
if ( positionCounter != statePositionCounter )
{
// At least 80% of the samples must be valid
if ( stateSamples * 100 / stateSamplesTotal >= 80 )
{
// Reset the scan counter, all the keys have been iterated over
// Ideally this should reset at 128, however
// due to noise in the cabling, this often moves around
// The minimum this can possibly set to is 124 as there
// are keys to service at 123 (0x78)
// Usually, unless there is lots of interference,
// this should limit most of the noise.
if ( positionCounter >= 124 )
{
positionCounter = 0;
}
// Key Press Detected
// - Skip 0x00 to 0x0B (11) for better jitter immunity (as there are no keys mapped to those scancodes)
else if ( positionCounter > 0x0B )
{
char tmp[15];
hexToStr( positionCounter, tmp );
dPrintStrsNL( "Key: ", tmp );
// Make sure there aren't any duplicate keys
uint8_t c;
for ( c = 0; c < KeyIndex_BufferUsed; c++ )
if ( KeyIndex_Buffer[c] == positionCounter )
break;
// No duplicate keys, add it to the buffer
if ( c == KeyIndex_BufferUsed )
bufferAdd( positionCounter );
}
}
// Remove the key from the buffer
else if ( positionCounter < 124 && positionCounter > 0x0B )
{
// 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] == positionCounter )
{
// 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;
}
}
}
// Clear the state counters
stateSamples = 0;
stateSamplesTotal = 0;
statePositionCounter = positionCounter;
}
// Pull in a data sample for this read instance
if ( DATA_OUT & (1 <<DATA_PIN) )
stateSamples++;
stateSamplesTotal++;
// Check if the clock de-synchronized
// And reset
if ( positionCounter > 128 )
{
char tmp[15];
hexToStr( positionCounter, tmp );
erro_dPrint( "De-synchronization detected at: ", tmp );
errorLED( 1 );
positionCounter = 0;
KeyIndex_BufferUsed = 0;
// Clear the state counters
stateSamples = 0;
stateSamplesTotal = 0;
// A keyboard reset requires interrupts to be enabled
sei();
scan_resetKeyboard();
cli();
}
// Regardless of what happens, always return 0
return 0;
}
// Send data
uint8_t scan_sendData( uint8_t dataPayload )
{
return 0;
}
// Signal KeyIndex_Buffer that it has been properly read
void scan_finishedWithBuffer( uint8_t sentKeys )
{
}
// Signal that the keys have been properly sent over USB
void scan_finishedWithUSBBuffer( uint8_t sentKeys )
{
}
// Reset/Hold keyboard
// NOTE: Does nothing with the HP150
void scan_lockKeyboard( void )
{
}
// NOTE: Does nothing with the HP150
void scan_unlockKeyboard( void )
{
}
// Reset Keyboard
void scan_resetKeyboard( void )
{
info_print("Attempting to synchronize the keyboard, do not press any keys...");
errorLED( 1 );
// Do a proper keyboard reset (flushes the ripple counters)
RESET_PORT |= (1 << RESET_PIN);
_delay_us(10);
RESET_PORT &= ~(1 << RESET_PIN);
// Delay main keyboard scanning, until the bit counter is synchronized
uint8_t synchronized = 0;
while ( !synchronized )
{
// Only use as a valid signal
// Check if there was a position change
if ( positionCounter != statePositionCounter )
{
// At least 80% of the samples must be valid
if ( stateSamples * 100 / stateSamplesTotal >= 80 )
{
// Read the current data value
if ( DATA_OUT & (1 << DATA_PIN) )
{
// Check if synchronized
// There are 128 positions to scan for with the HP150 keyboard protocol
if ( positionCounter == 128 )
synchronized = 1;
positionCounter = 0;
}
}
// Clear the state counters
stateSamples = 0;
stateSamplesTotal = 0;
statePositionCounter = positionCounter;
}
}
info_print("Keyboard Synchronized!");
}