/* Copyright (C) 2011-2013 by Joseph Makuch
 * Additions by Jacob Alexander (2013)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3.0 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

// ----- Includes -----

// Compiler Includes
#include <Lib/ScanLib.h>

// Project Includes
#include <led.h>
#include <print.h>

// Local Includes
#include "scan_loop.h"



// ----- Defines -----

// TODO dfj defines...needs commenting and maybe some cleaning...
#define MAX_PRESS_DELTA_MV 470
#define THRESHOLD_MV (MAX_PRESS_DELTA_MV >> 1)
//(2560 / (0x3ff/2)) ~= 5
#define MV_PER_ADC 5
// 5

#define THRESHOLD (THRESHOLD_MV / MV_PER_ADC)

#define BUMP_DETECTION 0
#define BUMP_THRESHOLD 0x50
#define BUMP_REST_US 1200

#define STROBE_SETTLE 1
#define MUX_SETTLE 1

#define TEST_KEY_STROBE (0x05)
#define TEST_KEY_MASK (1 << 0)

#define ADHSM 7

#define RIGHT_JUSTIFY 0
#define LEFT_JUSTIFY (0xff)

// set left or right justification here:
#define JUSTIFY_ADC RIGHT_JUSTIFY
#define ADLAR_MASK (1 << ADLAR)

#ifdef JUSTIFY_ADC
#define ADLAR_BITS ((ADLAR_MASK) & (JUSTIFY_ADC))
#else // defaults to right justification.
#define ADLAR_BITS 0
#endif

// full muxmask
#define FULL_MUX_MASK ((1 << MUX0) | (1 << MUX1) | (1 << MUX2) | (1 << MUX3) | (1 << MUX4))

// F0-f7 pins only muxmask.
#define MUX_MASK ((1 << MUX0) | (1 << MUX1) | (1 << MUX2))

// Strobe Masks
#define D_MASK (0xff)
#define E_MASK (0x03)
#define C_MASK (0xff)

// set ADC clock prescale
#define PRESCALE_MASK ((1 << ADPS0) | (1 << ADPS1) | (1 << ADPS2))
#define PRESCALE_SHIFT (ADPS0)
#define PRESCALE 3

// TODO Remove this define when unnecessary -HaaTa
#define STROBE_LINES 16

#define MUXES_COUNT 8
#define MUXES_COUNT_XSHIFT 3

#define WARMUP_LOOPS ( 1024 )
#define WARMUP_STOP (WARMUP_LOOPS - 1)

#define SAMPLES 10
#define SAMPLE_OFFSET ((SAMPLES) - MUXES_COUNT)
#define SAMPLE_CONTROL 3

// TODO Figure out calculation or best way to determine at startup -HaaTa
//#define DEFAULT_KEY_BASE 0xc8
#define DEFAULT_KEY_BASE 0x95

#define KEY_COUNT ((STROBE_LINES) * (MUXES_COUNT))

#define RECOVERY_CONTROL 1
#define RECOVERY_SOURCE  0
#define RECOVERY_SINK    2

#define ON  1
#define OFF 0

// mix in 1/4 of the current average to the running average. -> (@mux_mix = 2)
#define MUX_MIX 2

#define IDLE_COUNT_MASK 0xff
#define IDLE_COUNT_SHIFT 8

// av = (av << shift) - av + sample; av >>= shift
// e.g. 1 -> (av + sample) / 2 simple average of new and old
//      2 -> (3 * av + sample) / 4 i.e. 3:1 mix of old to new.
//      3 -> (7 * av + sample) / 8 i.e. 7:1 mix of old to new.
#define KEYS_AVERAGES_MIX_SHIFT 3



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

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

// Select mux
#define SET_FULL_MUX(X) ((ADMUX) = (((ADMUX) & ~(FULL_MUX_MASK)) | ((X) & (FULL_MUX_MASK))))



// ----- 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;


// TODO dfj variables...needs cleaning up and commenting
volatile uint16_t full_av = 0;

uint8_t ze_strober = 0;

uint16_t samples [SAMPLES];

uint16_t adc_mux_averages   [MUXES_COUNT];
uint16_t adc_strobe_averages[STROBE_LINES];

uint8_t cur_keymap[STROBE_LINES];

uint8_t keymap_change;

uint16_t threshold = 0x25; // HaaTa Hack -TODO
//uint16_t threshold = 0x16; // HaaTa Hack -TODO
//uint16_t threshold = THRESHOLD;

uint8_t column = 0;

uint16_t keys_averages_acc[KEY_COUNT];
uint16_t keys_averages[KEY_COUNT];

uint8_t full_samples[KEY_COUNT];

// TODO: change this to 'booting', then count down.
uint16_t boot_count = 0;

uint16_t idle_count = 0;
uint8_t idle = 1;

uint8_t error = 0;
uint16_t error_data = 0;

uint16_t mux_averages[MUXES_COUNT];
uint16_t strobe_averages[STROBE_LINES];

uint8_t dump_count = 0;

uint16_t db_delta = 0;
uint8_t  db_sample = 0;
uint16_t db_threshold = 0;



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

void dump( void );

void recovery( uint8_t on );

int sampleColumn( uint8_t column );

void setup_ADC( void );

void strobe_w( uint8_t strobe_num );

uint8_t testColumn( uint8_t strobe );



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

// Initial setup for cap sense controller
inline void scan_setup()
{
	// TODO dfj code...needs cleanup + commenting...
	setup_ADC();

	DDRC  = C_MASK;
	PORTC = 0;
	DDRD  = D_MASK;
	PORTD = 0;
	DDRE  = E_MASK;
	PORTE = 0 ;


	// TODO all this code should probably be in scan_resetKeyboard
	for (int i=0; i < STROBE_LINES; ++i) {
		cur_keymap[i] = 0;
	}

	for(int i=0; i < MUXES_COUNT; ++i) {
		adc_mux_averages[i] = 0x20; // experimentally determined.
	}
	for(int i=0; i < STROBE_LINES; ++i) {
		adc_strobe_averages[i] = 0x20; // yup.
	}

	for(int i=0; i < KEY_COUNT; ++i) {
		keys_averages[i] = DEFAULT_KEY_BASE;
		keys_averages_acc[i] = (DEFAULT_KEY_BASE);
	}

	/** warm things up a bit before we start collecting data, taking real samples. */
	for(uint8_t i = 0; i < STROBE_LINES; ++i) {
		sampleColumn(i);
	}


	// Reset the keyboard before scanning, we might be in a wierd state
	// Also sets the KeyIndex_BufferUsed to 0
	scan_resetKeyboard();
}


// Main Detection Loop
// This is where the important stuff happens
inline uint8_t scan_loop()
{
	// TODO dfj code...needs commenting + cleanup...
	uint8_t strober = 0;
	uint32_t full_av_acc = 0;

	for (strober = 0; strober < STROBE_LINES; ++strober)
	{

		uint8_t tries = 1;
		while ( tries++ && sampleColumn( strober ) ) { tries &= 0x7; } // don't waste this one just because the last one was poop.
		column = testColumn(strober);

		idle |= column; // if column has any pressed keys, then we are not idle.

		if( column != cur_keymap[strober] && ( boot_count >= WARMUP_LOOPS ) )
		{
			cur_keymap[strober] = column;
			keymap_change = 1;

			// The keypresses on this strobe are now know, send them right away
			for ( uint8_t mux = 0; mux < MUXES_COUNT; ++mux )
			{
				if ( column & (1 << mux) )
				{
					uint8_t key = (strober << MUXES_COUNT_XSHIFT) + mux;

					// Add to the Macro processing buffer
					// Automatically handles converting to a USB code and sending off to the PC
					//bufferAdd( key );

					printHex( key );
					print("\n");
				}
			}
		}

		idle |= keymap_change; // if any keys have changed inc. released, then we are not idle.

		if ( error == 0x50 )
		{
			error_data |= (((uint16_t)strober) << 12);
		}

		uint8_t strobe_line = strober << MUXES_COUNT_XSHIFT;
		for ( int i = 0; i < MUXES_COUNT; ++i )
		{
			// discard sketchy low bit, and meaningless high bits.
			uint8_t sample = samples[SAMPLE_OFFSET + i] >> 1;
			full_samples[strobe_line + i] = sample;
			keys_averages_acc[strobe_line + i] += sample;
		}

		strobe_averages[strober] = 0;
		for ( uint8_t i = SAMPLE_OFFSET; i < ( SAMPLE_OFFSET + MUXES_COUNT ); ++i )
		{
			full_av_acc += (samples[i]);
#ifdef COLLECT_STROBE_AVERAGES
			mux_averages[i - SAMPLE_OFFSET] += samples[i];
			strobe_averages[strober] += samples[i];
#endif
		}

#ifdef COLLECT_STROBE_AVERAGES
		adc_strobe_averages[strober] += strobe_averages[strober] >> 3;
		adc_strobe_averages[strober] >>= 1;

		/** test if we went negative. */
		if ( ( adc_strobe_averages[strober] & 0xFF00 ) && ( boot_count >= WARMUP_LOOPS ) )
		{
			error = 0xf; error_data = adc_strobe_averages[strober];
		}
#endif
	} // for strober

#ifdef VERIFY_TEST_PAD
	// verify test key is not down.
	if ( ( cur_keymap[TEST_KEY_STROBE] & TEST_KEY_MASK ) )
	{
		error = 0x05;
		error_data = cur_keymap[TEST_KEY_STROBE] << 8;
		error_data += full_samples[TEST_KEY_STROBE * 8];
		//threshold++;
	}
#endif

#ifdef COLLECT_STROBE_AVERAGES
	// calc mux averages.
	if ( boot_count < WARMUP_LOOPS )
	{
		full_av += (full_av_acc >> (7));
		full_av >>= 1;
		full_av_acc = 0;

		for ( int i = 0; i < MUXES_COUNT; ++i )
		{
			adc_mux_averages[i] = (adc_mux_averages[i] << MUX_MIX) - adc_mux_averages[i];
			adc_mux_averages[i] += (mux_averages[i] >> 4);
			adc_mux_averages[i] >>= MUX_MIX;

			mux_averages[i] = 0;
		}
	}
#endif

	/** aggregate if booting, or if idle;
	 * else, if not booting, check for dirty USB.
	 * */

	idle_count++;
	idle_count &= IDLE_COUNT_MASK;

	// Warm up voltage references
	if ( boot_count < WARMUP_LOOPS )
	{
		boot_count++;

		switch ( boot_count )
		{
		// First loop
		case 1:
			// Show msg at first iteration only
			info_msg("Warming up the voltage references");
			break;
		// Middle iterations
		case 300:
		case 600:
		case 900:
		case 1200:
			print(".");
			break;
		// Last loop
		case WARMUP_STOP:
			print("\n");
			info_msg("Warmup finished using ");
			printInt16( WARMUP_LOOPS );
			print(" iterations\n");
			break;
		}
	}
	else
	{
		// Reset accumulators and idle flag/counter
		if ( keymap_change )
		{
			for ( uint8_t c = 0; c < KEY_COUNT; ++c ) { keys_averages_acc[c] = 0; }
			idle_count = 0;
			idle = 0;

			keymap_change = 0;
		}

		if ( !idle_count )
		{
			if( idle )
			{
				// aggregate
				for ( uint8_t i = 0; i < KEY_COUNT; ++i )
				{
					uint16_t acc = keys_averages_acc[i] >> IDLE_COUNT_SHIFT;
					uint32_t av = keys_averages[i];

					av = (av << KEYS_AVERAGES_MIX_SHIFT) - av + acc;
					av >>= KEYS_AVERAGES_MIX_SHIFT;

					keys_averages[i] = av;
					keys_averages_acc[i] = 0;
				}
			}

			if ( boot_count >= WARMUP_LOOPS )
			{
				dump();
			}

			sampleColumn(0x0); // to resync us if we dumped a mess 'o text.
		}

	}

	// Error case, should not occur in normal operation
	if ( error )
	{
		erro_msg("Problem detected... ");

		// Keymap scan debug
		for ( uint8_t i = 0; i < STROBE_LINES; ++i )
		{
				printHex(cur_keymap[i]);
				print(" ");
		}

		print(" : ");
		printHex(error);
		error = 0;
		print(" : ");
		printHex(error_data);
		error_data = 0;

		// Display keymaps and other debug information if warmup completede
		if ( boot_count >= WARMUP_LOOPS )
		{
			dump();
		}
	}


	// Return non-zero if macro and USB processing should be delayed
	// Macro processing will always run if returning 0
	// USB processing only happens once the USB send timer expires, if it has not, scan_loop will be called
	//  after the macro processing has been completed
	return 0;
}


// Reset Keyboard
void scan_resetKeyboard( void )
{
	// Empty buffer, now that keyboard has been reset
	KeyIndex_BufferUsed = 0;
}


// Send data to keyboard
// NOTE: Only used for converters, since the scan module shouldn't handle sending data in a controller
uint8_t scan_sendData( uint8_t dataPayload )
{
	return 0;
}


// Reset/Hold keyboard
// NOTE: Only used for converters, not needed for full controllers
void scan_lockKeyboard( void )
{
}

// NOTE: Only used for converters, not needed for full controllers
void scan_unlockKeyboard( void )
{
}


// Signal KeyIndex_Buffer that it has been properly read
// NOTE: Only really required for implementing "tricks" in converters for odd protocols
void scan_finishedWithBuffer( uint8_t sentKeys )
{
	// Convenient place to clear the KeyIndex_Buffer
	KeyIndex_BufferUsed = 0;
	return;
}


// Signal KeyIndex_Buffer that it has been properly read and sent out by the USB module
// NOTE: Only really required for implementing "tricks" in converters for odd protocols
void scan_finishedWithUSBBuffer( uint8_t sentKeys )
{
	return;
}


void _delay_loop( uint8_t __count )
{
	__asm__ volatile (
		"1: dec %0" "\n\t"
		"brne 1b"
		: "=r" (__count)
		: "0" (__count)
	);
}


void setup_ADC()
{
	// disable adc digital pins.
	DIDR1 |= (1 << AIN0D) | (1<<AIN1D); // set disable on pins 1,0.
	DDRF = 0x0;
	PORTF = 0x0;
	uint8_t mux = 0 & 0x1f; // 0 == first. // 0x1e = 1.1V ref.

	// 0 = external aref 1,1 = 2.56V internal ref
	uint8_t aref = ((1 << REFS1) | (1 << REFS0)) & ((1 << REFS1) | (1 << REFS0));
	uint8_t adate = (1 << ADATE) & (1 << ADATE); // trigger enable
	uint8_t trig = 0 & ((1 << ADTS0) | (1 << ADTS1) | (1 << ADTS2)); // 0 = free running
	// ps2, ps1 := /64 ( 2^6 ) ps2 := /16 (2^4), ps1 := 4, ps0 :=2, PS1,PS0 := 8 (2^8)
	uint8_t prescale = ( ((PRESCALE) << PRESCALE_SHIFT) & PRESCALE_MASK ); // 001 == 2^1 == 2
	uint8_t hispeed = (1 << ADHSM);
	uint8_t en_mux = (1 << ACME);

	ADCSRA = (1 << ADEN) | prescale; // ADC enable

	// select ref.
	//ADMUX |= ((1 << REFS1) | (1 << REFS0)); // 2.56 V internal.
	//ADMUX |= ((1 << REFS0) ); // Vcc with external cap.
	//ADMUX &= ~((1 << REFS1) | (1 << REFS0)); // 0,0 : aref.
	ADMUX = aref | mux | ADLAR_BITS;

	// set free-running
	ADCSRA |= adate; // trigger enable
	ADCSRB  = en_mux | hispeed | trig | (ADCSRB & ~((1 << ADTS0) | (1 << ADTS1) | (1 << ADTS2))); // trigger select free running

	ADCSRA |= (1 << ADEN); // ADC enable
	ADCSRA |= (1 << ADSC); // start conversions q
}


void recovery( uint8_t on )
{
	DDRB  |=  (1 << RECOVERY_CONTROL);
	PORTB &= ~(1 << RECOVERY_SINK);   // SINK always zero
	DDRB  &= ~(1 << RECOVERY_SOURCE); // SOURCE high imp

	if ( on )
	{
		// set strobes to sink to gnd.
		DDRC |= C_MASK;
		DDRD |= D_MASK;
		DDRE |= E_MASK;

		PORTC &= ~C_MASK;
		PORTD &= ~D_MASK;
		PORTE &= ~E_MASK;

		DDRB  |= (1 << RECOVERY_SINK);	 // SINK pull
		PORTB |= (1 << RECOVERY_CONTROL);
		PORTB |= (1 << RECOVERY_SOURCE); // SOURCE high
		DDRB  |= (1 << RECOVERY_SOURCE);
	}
	else
	{
		PORTB &= ~(1 << RECOVERY_CONTROL);
		DDRB  &= ~(1 << RECOVERY_SOURCE);
		PORTB &= ~(1 << RECOVERY_SOURCE); // SOURCE low
		DDRB  &= ~(1 << RECOVERY_SINK);	  // SINK high-imp
	}
}


void hold_sample( uint8_t on )
{
	if ( !on )
	{
		PORTB |= (1 << SAMPLE_CONTROL);
		DDRB  |= (1 << SAMPLE_CONTROL);
	}
	else
	{
		DDRB  |=  (1 << SAMPLE_CONTROL);
		PORTB &= ~(1 << SAMPLE_CONTROL);
	}
}


void strobe_w( uint8_t strobe_num )
{
	PORTC &= ~(C_MASK);
	PORTD &= ~(D_MASK);
	PORTE &= ~(E_MASK);

#ifdef SHORT_C
	//strobe_num = 15 - strobe_num;
#endif
	/*
	printHex( strobe_num );
	print(" ");
	strobe_num = 9 - strobe_num;
	printHex( strobe_num );
	print("\n");
	*/

	switch(strobe_num) {

	// XXX Kishsaver strobe (note that D0, D1 are not used)
	case 0: PORTD |= (1 << 0); break;
	case 1: PORTD |= (1 << 1); break;
	case 2: PORTD |= (1 << 2); break;
	case 3: PORTD |= (1 << 3); break;
	case 4: PORTD |= (1 << 4); break;
	case 5: PORTD |= (1 << 5); break;

	// TODO REMOVEME
	case 6: PORTD |= (1 << 6); break;
	case 7: PORTD |= (1 << 7); break;
	case 8: PORTE |= (1 << 0); break;
	case 9: PORTE |= (1 << 1); break;
	//case 15: PORTC |= (1 << 5); break; // Test strobe on kishsaver

#if 0
	// XXX Kishsaver strobe (note that D0, D1 are not used)
	case 0: PORTD |= (1 << 2); break;
	case 1: PORTD |= (1 << 3); break;
	case 2: PORTD |= (1 << 4); break;
	case 3: PORTD |= (1 << 5); break;

	// TODO REMOVEME
	case 4: PORTD |= (1 << 6); break;
	case 5: PORTD |= (1 << 7); break;
	case 6: PORTE |= (1 << 0); break;
	case 7: PORTE |= (1 << 1); break;
	case 15: PORTC |= (1 << 5); break; // Test strobe on kishsaver
#endif
/*
#ifdef ALL_D

	case 6: PORTD |= (1 << 6); break;
	case 7: PORTD |= (1 << 7); break;

	case 8:  PORTC |= (1 << 0); break;
	case 9:  PORTC |= (1 << 1); break;
	case 10: PORTC |= (1 << 2); break;
	case 11: PORTC |= (1 << 3); break;
	case 12: PORTC |= (1 << 4); break;
	case 13: PORTC |= (1 << 5); break;
	case 14: PORTC |= (1 << 6); break;
	case 15: PORTC |= (1 << 7); break;

	case 16: PORTE |= (1 << 0); break;
	case 17: PORTE |= (1 << 1); break;

#else
#ifdef SHORT_D

	case 6: PORTE |= (1 << 0); break;
	case 7: PORTE |= (1 << 1); break;

	case 8:  PORTC |= (1 << 0); break;
	case 9:  PORTC |= (1 << 1); break;
	case 10: PORTC |= (1 << 2); break;
	case 11: PORTC |= (1 << 3); break;
	case 12: PORTC |= (1 << 4); break;
	case 13: PORTC |= (1 << 5); break;
	case 14: PORTC |= (1 << 6); break;
	case 15: PORTC |= (1 << 7); break;

#else
#ifdef SHORT_C

	case 6: PORTD |= (1 << 6); break;
	case 7: PORTD |= (1 << 7); break;

	case 8: PORTE |= (1 << 0); break;
	case 9: PORTE |= (1 << 1); break;

	case 10:  PORTC |= (1 << 0); break;
	case 11:  PORTC |= (1 << 1); break;
	case 12: PORTC |= (1 << 2); break;
	case 13: PORTC |= (1 << 3); break;
	case 14: PORTC |= (1 << 4); break;
	case 15: PORTC |= (1 << 5); break;

	case 16: PORTC |= (1 << 6); break;
	case 17: PORTC |= (1 << 7); break;

#endif
#endif
#endif
*/

	default:
		break;
	}


#if 0 // New code from dfj -> still needs redoing for kishsaver and autodetection of strobes
#ifdef SHORT_C
	strobe_num = 15 - strobe_num;
#endif

#ifdef SINGLE_COLUMN_TEST
	strobe_num = 5;
#endif

	switch(strobe_num) {

	case 0: PORTD |= (1 << 0); DDRD &= ~(1 << 0); break;
	case 1: PORTD |= (1 << 1); DDRD &= ~(1 << 1); break;
	case 2: PORTD |= (1 << 2); DDRD &= ~(1 << 2); break;
	case 3: PORTD |= (1 << 3); DDRD &= ~(1 << 3); break;
	case 4: PORTD |= (1 << 4); DDRD &= ~(1 << 4); break;
	case 5: PORTD |= (1 << 5); DDRD &= ~(1 << 5); break;

#ifdef ALL_D

	case 6: PORTD |= (1 << 6); break;
	case 7: PORTD |= (1 << 7); break;

	case 8:  PORTC |= (1 << 0); break;
	case 9:  PORTC |= (1 << 1); break;
	case 10: PORTC |= (1 << 2); break;
	case 11: PORTC |= (1 << 3); break;
	case 12: PORTC |= (1 << 4); break;
	case 13: PORTC |= (1 << 5); break;
	case 14: PORTC |= (1 << 6); break;
	case 15: PORTC |= (1 << 7); break;

	case 16: PORTE |= (1 << 0); break;
	case 17: PORTE |= (1 << 1); break;

#else
#ifdef SHORT_D

	case 6: PORTE |= (1 << 0); break;
	case 7: PORTE |= (1 << 1); break;

	case 8:  PORTC |= (1 << 0); break;
	case 9:  PORTC |= (1 << 1); break;
	case 10: PORTC |= (1 << 2); break;
	case 11: PORTC |= (1 << 3); break;
	case 12: PORTC |= (1 << 4); break;
	case 13: PORTC |= (1 << 5); break;
	case 14: PORTC |= (1 << 6); break;
	case 15: PORTC |= (1 << 7); break;

#else
#ifdef SHORT_C

	case 6: PORTD |= (1 << 6); DDRD &= ~(1 << 6); break;
	case 7: PORTD |= (1 << 7); DDRD &= ~(1 << 7); break;

	case 8: PORTE |= (1 << 0); DDRE &= ~(1 << 0); break;
	case 9: PORTE |= (1 << 1); DDRE &= ~(1 << 1); break;

	case 10:  PORTC |= (1 << 0); DDRC &= ~(1 << 0); break;
	case 11:  PORTC |= (1 << 1); DDRC &= ~(1 << 1); break;
	case 12: PORTC |= (1 << 2); DDRC &= ~(1 << 2); break;
	case 13: PORTC |= (1 << 3); DDRC &= ~(1 << 3); break;
	case 14: PORTC |= (1 << 4); DDRC &= ~(1 << 4); break;
	case 15: PORTC |= (1 << 5); DDRC &= ~(1 << 5); break;

	case 16: PORTC |= (1 << 6); DDRC &= ~(1 << 6); break;
	case 17: PORTC |= (1 << 7); DDRC &= ~(1 << 7); break;

#endif
#endif
#endif

	default:
		break;
	}

#endif


}


inline uint16_t getADC(void)
{
	ADCSRA |= (1 << ADIF); // clear int flag by writing 1.

	//wait for last read to complete.
	while ( !( ADCSRA & (1 << ADIF) ) );

	return ADC; // return sample
}


int sampleColumn_8x( uint8_t column, uint16_t * buffer )
{
	// ensure all probe lines are driven low, and chill for recovery delay.
	ADCSRA |= (1 << ADEN) | (1 << ADSC); // enable and start conversions

	PORTC &= ~C_MASK;
	PORTD &= ~D_MASK;
	PORTE &= ~E_MASK;

	PORTF = 0;
	DDRF  = 0;

	recovery(OFF);
	strobe_w(column);

	hold_sample(OFF);
	SET_FULL_MUX(0);

	for ( uint8_t i = 0; i < STROBE_SETTLE; ++i ) { getADC(); }

	hold_sample(ON);

#undef MUX_SETTLE

#if (MUX_SETTLE)
	for ( uint8_t mux = 0; mux < 8; ++mux )
	{
		SET_FULL_MUX(mux); // our sample will use this

		// wait for mux to settle.
		for ( uint8_t i = 0; i < MUX_SETTLE; ++i ) { getADC(); }

		// retrieve current read.
		buffer[mux] = getADC();
	}
#else
	uint8_t mux = 0;
	SET_FULL_MUX(mux);
	getADC(); // throw away; unknown mux.
	do {
		SET_FULL_MUX(mux + 1); // our *next* sample will use this

		// retrieve current read.
		buffer[mux] = getADC();
		mux++;

	} while (mux < 8);

#endif
	hold_sample(OFF);
	recovery(ON);

	// turn off adc.
	ADCSRA &= ~(1 << ADEN);

	// pull all columns' strobe-lines low.
	DDRC |= C_MASK;
	DDRD |= D_MASK;
	DDRE |= E_MASK;

	PORTC &= ~C_MASK;
	PORTD &= ~D_MASK;
	PORTE &= ~E_MASK;

	return 0;
}


int sampleColumn( uint8_t column )
{
	int rval = 0;

	rval = sampleColumn_8x( column, samples + SAMPLE_OFFSET );

#if (BUMP_DETECTION)
	for ( uint8_t i = 0; i < 8; ++i )
	{
		if ( samples[SAMPLE_OFFSET + i] - adc_mux_averages[i] > BUMP_THRESHOLD )
		{
			// was a hump
			_delay_us(BUMP_REST_US);
			rval++;
			error = 0x50;
			error_data = samples[SAMPLE_OFFSET +i]; //  | ((uint16_t)i << 8);
			return rval;
		}
	}
#endif

	return rval;
}


uint8_t testColumn( uint8_t strobe )
{
	uint8_t column = 0;
	uint8_t bit = 1;
	for ( uint8_t i = 0; i < MUXES_COUNT; ++i )
	{
		uint16_t delta = keys_averages[(strobe << MUXES_COUNT_XSHIFT) + i];

		if ( (db_sample = samples[SAMPLE_OFFSET + i] >> 1) > (db_threshold = threshold) + (db_delta = delta) )
		{
			column |= bit;
		}

#ifdef THRESHOLD_VERIFICATION
		if ( db_sample > 0xA0 )
		{
			printHex( db_sample );
			print(" : ");
			printHex( db_threshold );
			print(" : ");
			printHex( db_delta );
			print(" :: ");
			printHex( column );
			print(" : ");
			printHex( strobe );
			print(NL);
		}
#endif

		bit <<= 1;
	}
	return column;
}


void dump(void) {

#ifdef DEBUG_FULL_SAMPLES_AVERAGES
	// we don't want to debug-out during the measurements.
	if ( !dump_count )
	{
		// Averages currently set per key
		for ( int i = 0; i < KEY_COUNT; ++i )
		{
			if ( !(i & 0x0f) )
			{
				print("\n");
			}
			else if ( !(i & 0x07) )
			{
				print("  ");
			}

			print(" ");
			printHex( keys_averages[i] );
		}

		print("\n");

		// Previously read full ADC scans?
		for ( int i = 0; i< KEY_COUNT; ++i)
		{
			if ( !(i & 0x0f) )
			{
				print("\n");
			}
			else if ( !(i & 0x07) )
			{
				print("  ");
			}

			print(" ");
			printHex(full_samples[i]);
		}
	}
#endif

#ifdef DEBUG_STROBE_SAMPLES_AVERAGES
	// Per strobe information
	uint8_t cur_strober = ze_strober;
	print("\n");

	printHex(cur_strober);

	// Previously read ADC scans on current strobe
	print(" :");
	for ( uint8_t i = 0; i < MUXES_COUNT; ++i )
	{
		print(" ");
		printHex(full_samples[(cur_strober << MUXES_COUNT_XSHIFT) + i]);
	}

	// Averages current set on current strobe
	print(" :");

	for ( uint8_t i = 0; i < MUXES_COUNT; ++i )
	{
		print(" ");
		printHex(keys_averages[(cur_strober << MUXES_COUNT_XSHIFT) + i]);
	}

#endif

#ifdef DEBUG_DELTA_SAMPLE_THRESHOLD
	print("\n");
	printHex( db_delta );
	print(" ");
	printHex( db_sample );
	print(" ");
	printHex( db_threshold );
	print(" ");
	printHex( column );
#endif

#ifdef DEBUG_USB_KEYMAP
	print("\n      ");

	// Current keymap values
	for ( uint8_t i = 0; i < STROBE_LINES; ++i )
	{
		printHex(cur_keymap[i]);
		print(" ");
	}
#endif

	ze_strober++;
	ze_strober &= 0xf;

	dump_count++;
	dump_count &= 0x0f;
}