Finishing up the Epson QX-10 module

[kiibohd-controller.git] / Scan / EpsonQX-10 / scan_loop.c

/* Copyright (C) 2011 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 CLOCK_PORT PORTB
#define CLOCK_DDR   DDRB
#define CLOCK_PIN      0


// ----- Macros -----

// Make sure we haven't overflowed the buffer
#define bufferAdd(byte) \
                if ( KeyIndex_BufferUsed < KEYBOARD_BUFFER ) \
                        KeyIndex_Buffer[KeyIndex_BufferUsed++] = byte

#define setLED(id, status) \
                status = status ? 0 : 1; \
                scan_setLED( id, status )



// ----- 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 currentWaveState = 0;

volatile uint8_t calcLED      = 0;
volatile uint8_t insertLED    = 0;
volatile uint8_t shiftLockLED = 0;
volatile uint8_t schedLED     = 0;
volatile uint8_t drawLED      = 0;



// ----- Function Declarations -----

void scan_diagnostics( void );
void processKeyValue( uint8_t keyValue );
void scan_diagnostics( void );
void scan_setRepeatStart( uint8_t n );
void scan_readSwitchStatus( void );
void scan_repeatControl( uint8_t on );
void scan_enableKeyboard( uint8_t enable );
void scan_setRepeatRate( uint8_t n );
void scan_setLED( uint8_t ledNumber, uint8_t on );
void scan_readLED( void );



// ----- Interrupt Functions -----

// Generates a constant external clock
ISR( TIMER1_COMPA_vect )
{
        if ( currentWaveState )
        {
                CLOCK_PORT &= ~(1 << CLOCK_PIN);
                currentWaveState--;
        }
        else
        {
                CLOCK_PORT |=  (1 << CLOCK_PIN);
                currentWaveState++;
        }
}

// USART Receive Buffer Full Interrupt
ISR(USART1_RX_vect)
{
        cli(); // Disable Interrupts

        uint8_t keyValue = 0x00;

        // Read the raw packet from the USART
        keyValue = UDR1;

        // Debug
        char tmpStr[6];
        hexToStr( keyValue, tmpStr );
        dPrintStrs( tmpStr, " " );

        // Process the scancode
        if ( keyValue != 0x00 )
                processKeyValue( keyValue );

        sei(); // Re-enable Interrupts
}



// ----- Functions -----

// Setup
inline void scan_setup()
{
        // Setup Timer Pulse (16 bit)
        // 16 MHz / (2 * Prescaler * (1 + OCR1A)) = 1204.8 baud (820 us)
        // Prescaler is 1
        /*
        TCCR1B = 0x09;
        OCR1AH = 0x19;
        OCR1AL = 0xEF;
        TIMSK1 = (1 << OCIE1A);
        CLOCK_DDR = (1 << CLOCK_PIN);
        */
        // 16 MHz / (2 * Prescaler * (1 + OCR1A)) = 1200.1 baud
        // Prescaler is 1
        // Twice every 1200 baud (actually 1200.1, timer isn't accurate enough)
        // This is close to 820 us, but a bit slower
        cli();
        TCCR1B = 0x09;
        OCR1AH = 0x1A;
        OCR1AL = 0x09;
        TIMSK1 = (1 << OCIE1A);
        CLOCK_DDR = (1 << CLOCK_PIN);


        // Setup the the USART interface for keyboard data input
        
        // Setup baud rate
        // 16 MHz / ( 16 * Baud ) = UBRR
        // Baud <- 1200 as per the spec (see datasheet archives), rounding to 1200.1 (as that's as accurate as the timer can be)
        // Thus UBRR = 833.26 -> round to 833
        uint16_t baud = 833; // Max setting of 4095
        UBRR1H = (uint8_t)(baud >> 8);
        UBRR1L = (uint8_t)baud;

        // Enable the receiver, transitter, and RX Complete Interrupt
        UCSR1B = 0x98;

        // Set frame format: 8 data, no stop bits or parity
        // Synchrounous USART mode
        // Tx Data on Falling Edge, Rx on Rising
        UCSR1C = 0x47;
        sei();

        // Reset the keyboard before scanning, we might be in a wierd state
        _delay_ms( 50 );
        scan_resetKeyboard();

        _delay_ms( 5000 ); // Wait for the reset command to finish enough for new settings to take hold afterwards
        scan_setRepeatRate( 0x00 ); // Set the fastest repeat rate
}


// Main Detection Loop
// Nothing is required here with the Epson QX-10 Keyboards as the interrupts take care of the inputs
inline uint8_t scan_loop()
{
        return 0;
}

// TODO
void processKeyValue( uint8_t keyValue )
{
        // Detect LED Status
        uint8_t inputType = keyValue & 0xC0;

        // Determine the input type
        switch ( inputType )
        {
        // LED Status
        case 0xC0:
                // Binary Representation: 1100 llln
                // Hex Range: 0xC0 to 0xCF
                // - First 3 bits determine which LED (0 to 7)
                // - Last bit is whether the LED is On (1) or Off (0)
                // 000 - N/A (A)
                // 001 - N/A (B)
                // 010 - INSERT
                // 011 - SHIFT LOCK
                // 100 - N/A (C)
                // 101 - DRAW
                // 110 - SCHED
                // 111 - CALC
                break;

        // SW (Switch) Status
        case 0x80:
        {
                // Binary Representation: 1000 dddn
                // Hex Range: 0x80 to 0x8F
                // - First 3 bits determine which DB (KRTN) (See datasheet)
                // - Last bit is whether the key is enabled
                // 000 - N/A?
                // 001 - N/A?
                // 010 - Right SHIFT
                // 011 - Left SHIFT
                // 100 - N/A?
                // 101 - Left CTRL
                // 110 - GRPH SHIFT
                // 111 - Right CTRL

                // Detect Modifier Press/Release
                uint8_t press = keyValue & 0x01;

                // Modifier Press Detected
                if ( press )
                {
                        // 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;
                        }
                }
                // Modifier Release Detected
                else
                {
                        uint8_t actualKeyValue = keyValue | 0x01;

                        // 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] == actualKeyValue )
                                {
                                        // 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 );
                        }
                }
                break;
        }

        // Key code
        default:
                // Binary Representation: 0ddd pppp
                // Hex Range: 0x00 to 0x7F
                // - First 3 bits determine which DB (KRTN) (See datasheet)
                // - Last 4 bits corresond to the KSC signals (P13, P12, P11, P10 respectively)
                // Or, that can be read as, each key has it's own keycode (with NO release code)
                // Modifiers are treated differently
                
                // Add the key to the buffer, if it isn't already in the current Key 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;
                }
                // Special Internal Key Mapping/Functions
                switch ( keyValue )
                {
                // LED Test
                case 0x0A: // CALC
                        setLED( 0x07, calcLED ); // 0x4F
                        break;
                case 0x0B: // SCHED
                        setLED( 0x0E, schedLED ); // 0x5D
                        break;
                case 0x0C: // DRAW
                        setLED( 0x0D, drawLED ); // 0x5B
                        break;
                case 0x42: // SHIFT LOCK
                        setLED( 0x0B, shiftLockLED ); // 0x57
                        break;
                case 0x5E: // INSERT
                        setLED( 0x02, insertLED ); // 0x45
                        break;

                /*
                // TEST
                case 0x51:
                        scan_resetKeyboard();
                        break;
                case 0x52:
                        scan_diagnostics();
                        break;
                case 0x53:
                        scan_setRepeatStart( 0x00 );
                        break;
                case 0x54:
                        scan_readSwitchStatus();
                        break;
                case 0x55:
                        scan_repeatControl( 0x00 );
                        break;
                case 0x56:
                        scan_repeatControl( 0x01 );
                        break;
                case 0x57:
                        scan_enableKeyboard( 0x00 );
                        break;
                case 0x58:
                        scan_enableKeyboard( 0x01 );
                        break;
                case 0x59:
                        scan_setRepeatRate( 0x00 );
                        break;
                case 0x5A:
                        scan_readLED();
                        break;
                */
                }
                break;
        }
}

// Send data
// See below functions for the input sequences for the Epson QX-10 Keyboard
uint8_t scan_sendData( uint8_t dataPayload )
{
        // Debug
        char tmpStr[6];
        hexToStr( dataPayload, tmpStr );
        info_dPrint( tmpStr, " " );

        UDR1 = dataPayload;
        return 0;
}

// Signal KeyIndex_Buffer that it has been properly read
inline void scan_finishedWithBuffer( void )
{
        return;
}

// Signal that the keys have been properly sent over USB
// For the Epson QX-10 only the modifier keys have release signals
// Therefore, only 5 keys could possibly be assigned as a modifiers
// The rest of the keys are single press (like the Kaypro keyboards)
//
// However, this differentiation causes complications on how the key signals are discarded and used
// The single keypresses must be discarded immediately, while the modifiers must be kept
inline 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;

        /* Non-working, too slow (too much traffic on the bus)
        // Poll the modifiers using an input command
        uint8_t oldBuffer = KeyIndex_BufferUsed;
        KeyIndex_BufferUsed = 0;
        if ( oldBuffer )
                scan_readSwitchStatus();
        */
}

// Reset/Hold keyboard
// Warning! This will cause the keyboard to not send any data, so you can't disable with a keypress
// The Epson QX-10 Keyboards have a command used to lock the keyboard output
void scan_lockKeyboard( void )
{
        scan_enableKeyboard( 0x00 );
}

void scan_unlockKeyboard( void )
{
        scan_enableKeyboard( 0x01 );
}

// Reset Keyboard
// Does the following
// - Clears the keycode buffer (32 characters)
// - Validates repeat function (what does this do?)
// - Sets repeat start time (500 ms)
// - Sets repeat interval (50 ms)
// - Turns off all LEDs
void scan_resetKeyboard( void )
{
        // Reset command for the QX-10 Keyboard
        scan_sendData( 0xE0 );

        // Empty buffer, now that keyboard has been reset
        KeyIndex_BufferUsed = 0;
}

// TODO Check
// Runs Diagnostics on the keyboard
// - First does a reset (see scan_resetKeyboard)
// - Blinks all of the LEDs one after another
// - Outputs 0x00 if no keys are pressed
// - Outputs 0xFF if any keys are being pressed
void scan_diagnostics( void )
{
        // Send reset command with diagnositics
        scan_sendData( 0xE7 );
}

// TODO Check
// Set Repeat Interval Start
// 300 ms + n * 25 ms
// Interval after which to start the repeated keys
void scan_setRepeatStart( uint8_t n )
{
        // Send command
        // Binary Representation: 000n nnnn
        // Hex boundaries 0x00 to 0x1F
        // 300 ms to 1075 ms (intervals of 25 ms)
        scan_sendData( n );
}

// Read Switch Status (preferential to actual keypress outputs)
// 000 - N/A?
// 001 - N/A?
// 010 - Right SHIFT
// 011 - Left SHIFT
// 100 - N/A?
// 101 - Left CTRL
// 110 - GRPH SHIFT
// 111 - Right CTRL
void scan_readSwitchStatus( void )
{
        scan_sendData( 0x80 );
}

// TODO Check
// Repeat Control
// 0x00 Stops repeat function
// 0x01 Enables repeat function
void scan_repeatControl( uint8_t on )
{
        // Send command
        // Binary Representation: 101X XXXn
        // Hex options: 0xA0 or 0xA1
        scan_sendData( 0xA0 | on );
}

// TODO Check
// Enable Sending Keyboard Data
// 0x00 Stops keycode transmission
// 0x01 Enables keycode transmission
void scan_enableKeyboard( uint8_t enable )
{
        // Send command
        // Binary Representation: 110X XXXn
        // Hex options: 0xC0 or 0xC1
        scan_sendData( 0xC0 | enable );
}

// Set Repeat Interval
// 30 ms + n * 5 ms
// Period between sending each repeated key after the initial interval
void scan_setRepeatRate( uint8_t n )
{
        // Send command
        // Binary Representation: 001n nnnn
        // Hex options: 0x00 to 0x1F
        // 30 ms to 185 ms (intervals of 5 ms)
        scan_sendData( 0x20 | n );
}

// Turn On/Off LED
// 0x00 LED Off
// 0x01 LED On
//
// 8 LEDs max (Note: 5 connected on my board, there is 1 position empty on the PCB for a total of 6)
// 0 to 7 (0x0 to 0x7)
void scan_setLED( uint8_t ledNumber, uint8_t on )
{
        // Send command
        // Binary Representation: 010l llln
        // Hex options: 0x40 to 0x4F
        // The spec is NOT accurate (especially about the "don't care" bit)
        // llll n - Usage
        // 0000 X - N/A (1)
        // 0001 X - N/A (2)
        // 0010 1 - INSERT On
        // 0011 0 - SHIFT LOCK Off
        // 0100 X - N/A (3)
        // 0101 0 - DRAW Off
        // 0110 0 - SCHED Off
        // 0111 1 - CALC On
        // 1000 X - N/A (1)
        // 1001 X - N/A (2)
        // 1010 0 - INSERT Off
        // 1011 1 - SHIFT LOCK On
        // 1100 X - N/A (3)
        // 1101 1 - DRAW On
        // 1110 1 - SCHED On
        // 1111 0 - CALC Off

        uint8_t off = 0;
        if ( !on )
        {
                off = 0x10;
        }
        scan_sendData( ( 0x40 | (ledNumber << 1) | on ) ^ off );
}

// Read LED Status
// High priority data output (may overwrite some keycode data)
void scan_readLED( void )
{
        scan_sendData( 0x7F );
}