Finished project (5045c63f) · Commits · Georgiana-Diana CIOCÎRDEL / pm-proiect

lab1.c

+67 −269

Original line number	Diff line number	Diff line
		@@ -2,9 +2,6 @@
		* Georgiana Diana Ciocirdel
		* Proiect PM 2015 - Guitar Tuner
		*
		* I am using bits of code from a 2007 project, written by Razvan Tataroiu. His
		* project can be found here:
		* https://sites.google.com/site/razvan784/proiectproiectareacumicroprocesoare
		*/

		#include "lcd.h"
		@@ -50,8 +47,7 @@

		/******************************************************************************/
		/* Tuner specific stuff. */
		#define PRESCALER 64
		#define MAX_QUEUE_LEN 254
		#define PRESCALER 256

		#define E 164.81
		#define A 220.00
		@@ -60,35 +56,19 @@
		#define B 493.88
		#define EH 659.26

		/* Two times the standard guitar guitar tunings as per
		* http://en.wikipedia.org/wiki/Guitar_tunings#Standard */
		float std_fr[] = {164.81, 220.00, 293.66, 391.99, 493.88, 659.26};
		char *str_std_fr[] = {"E ", "A ", "D ", "G ", "B ", "EH"};
		char chosen_string = 0;
		unsigned char queue[254], start, stop, size; /* Circular queue for samples. */

		#define LOG2 log(2.0)
		#define S_RATE ((float) F_CPU / 64.0 / 13.0)
		#define S_RATEI (F_CPU / 64 / 13)
		#define S_MIN_MAX (S_RATE / 10)

		unsigned int avg;
		char gain;
		char state;
		char top;
		char bot;
		char tmp_top;
		char tmp_bot;
		int count;
		int no_of_samples;
		int last_sample;
		float freq;
		char started;
		char err_disp;
		char ngainchg;
		char havetopbot;
		char txt[17];
		char notes[36]="dC dC#rD rD#mE fF fF#sG sG#lA lA#tB ";
		/******************************************************************************/

		/******************************************************************************/
		void timer1_init (void) {
		TCCR1B \|= (1 << CS12) \| /* Prescaler = 256 */
		(1 << WGM12); /* Clear on compare, TOP = OCR1A */
		TIMSK1 \|= ( 1<< OCIE1A);
		OCR1A = 31250; /* TOP */
		}

		void LCD_clear (void) {
		LCD_printAt (FST_LINE_FST_CHAR, EMPTY_LINE);
		@@ -104,19 +84,10 @@ void button_init (void) {
		PORT_BTN \|= (1 << BIT_BTN);
		}

		void ADC_init (void) {
		/* Enable interrupt on PA7. */
		DDRA \|= (1 << PA7);
		ADMUX = (1 << REFS0) \| /* Set VCC as reference. */
		(1 << ADLAR) \| /* Left-adjust the result in the ADC data register:
		* this saves the result in ADCH. */
		((1 << MUX0) \| (1 << MUX1) \| (1 << MUX2)); /* ADC7 as input. */
		ADCSRA = (1 << ADEN) \| /* Enable ADC. */
		(1 << ADSC) \| /* Enable free running conversions. */
		(1 << ADATE) \| /* Enable ADC autotrigger. */
		(1 << ADIE) \| /* Enable interruptions. */
		(1 << ADPS2) \| /* Set prescaler at 64. */
		(1 << ADPS1);
		void input_init (void) {
		DDRB &= ~(1 << PB7);
		PCICR \|= (1 << PCIE1);
		PCMSK1 \|= (1 << PCINT15);
		}

		void wait_for (int millisecs) {
		@@ -128,7 +99,7 @@ void wait_for (int millisecs) {
		}

		void refresh_snd_line (void) {
		LCD_printAt (SND_LINE_FST_CHAR + 7, "\|");
		LCD_printAt (SND_LINE_FST_CHAR, EMPTY_LINE);
		}

		void startup_LCD (void) {
		@@ -137,10 +108,8 @@ void startup_LCD (void) {
		/* Display welcome message and toggle LED.*/
		LCD_printAt (FST_LINE_FST_CHAR, "Welcome to");
		LCD_printAt (SND_LINE_FST_CHAR, "Guitar Tuner");
		//toggle_bit (PORT_LED, BIT_LED);
		toggle_bit (PORT_LED, BIT_LED);
		wait_for (2000);
		//toggle_bit (PORT_LED, BIT_LED);
		toggle_bit (PORT_LED, BIT_LED);
		LCD_clear ();

		@@ -156,6 +125,10 @@ void startup_LCD (void) {
		LCD_printAt (FST_LINE_FST_CHAR, "");
		}

		int count_down_up;
		int sum = 0;
		int count = 0;

		void move_cursor (void) {
		if ((PIN_BTN & (1 << BIT_BTN)) == 0) {
		chosen_string = (chosen_string + 1) % 6;
		@@ -164,201 +137,14 @@ void move_cursor (void) {
		toggle_bit (PORT_LED, BIT_LED);
		wait_for (300);
		toggle_bit (PORT_LED, BIT_LED);
		}
		}

		/*
		* I am hereby using parts of code from Razvan Tataroiu's project from 2007. His
		* project can be found here:
		* https://sites.google.com/site/razvan784/proiectproiectareacumicroprocesoare
		*/
		void process_sample (char curr_sample) {
		int x16; /* Used for computations => we need more precission. */
		char x; /* Will hold current sample value, after computations. */

		/* Increment number of samples. */
		no_of_samples++;

		/* Compute signal average with 20 bits precision:
		* avg = (avg * 4095 + (increased precision) smp ) / 4096 */
		avg = ((avg << 12) - avg + ((unsigned int) curr_sample << 12)) >> 12;

		/* After a gain change wait to stabilize external circuit and average. */
		if (ngainchg == FALSE) {
		//PORTD = 0xFF;//led on
		if (no_of_samples == 5 * S_MIN_MAX) {
		no_of_samples = 0;
		last_sample = 1;
		ngainchg = TRUE;
		tmp_top = 0;
		tmp_bot = 0;
		} else {
		return;
		}
		}

		/* Center on zero. */
		x16 = (int) curr_sample - (int) (avg >> 12); //decrease precision to 8 bits

		/* Saturate. */
		if (x16 < -128) {
		x16 = -128;
		}
		if (x16 > 127) {
		x16 = 127;
		}

		x = x16; //convert to 8 bits

		/* Compute top, bottom. */
		if (x > tmp_top) {
		tmp_top = x;
		}
		if (x < tmp_bot) {
		tmp_bot = x;
		}

		/* Update top, bottom every 100ms. */
		if (no_of_samples % (S_RATEI / 10) == 0) {
		top = tmp_top;
		bot = tmp_bot;
		tmp_top = 0;
		tmp_bot = 0;
		}

		/* Make at least one top, bot measurement after a gain change. */
		if (havetopbot == FALSE) {
		if (no_of_samples == S_MIN_MAX) {
		havetopbot = TRUE;
		no_of_samples = 0;
		//PORTD = 0x7F;//led off
		}
		return;
		}

		/* Schmitt trigger. */
		if (state == 1 && x < bot / 2) {
		state = 0;
		}

		if (state == 0 && x > top / 2) {
		state = 1;
		count++; /* transition count, and sample number of last transition */
		last_sample = no_of_samples;
		}

		/* frequency relative error = 1 / (sample number) */
		if (no_of_samples == 8192) {
		// 8-step external agc, hysterezis
		// perform agc change now, as next samples may come in delayed
		// due to float calculations and lcd display
		if (top == 127 \|\| bot == -128) {
		// decrease gain
		if (gain != 0b00000000) {
		err_disp = FALSE;
		gain -= 0b00100000;
		PORTA = gain;
		ngainchg = FALSE;
		havetopbot = FALSE;
		}
		}

		if (top < 16 && bot > -16) {
		// increase gain
		if (gain != 0b11100000) {
		//limit gain to e.g. 3 if it picks up too much noise through
		// microphone. leave at 8 if using a lower noise setup (e.g. plugging an electric guitar)
		gain += 0b00100000;
		PORTA = gain;
		ngainchg = 0;
		havetopbot = 0;
		} else {
		if(top < 8) {
		if (err_disp == FALSE) {
		LCD_clear ();
		LCD_printAt (SND_LINE_FST_CHAR, "ERROR NO SIGNAL");
		err_disp = TRUE;
		return;
		}
		} else {
		err_disp = 0;
		}
		}
		}

		// update frequency
		freq = S_RATE * count / last_sample;
		count_down_up = 0;
		sum = 0;
		count = 0;
		no_of_samples = 0;
		last_sample = 1;
		state = 0;

		// ftoa
		int frq = (int) freq;
		char frac = (char) ((freq - (float) frq) * 100);
		unsigned char ptr = 4;
		if (frq > 6000) {
		frq = 9999;
		}

		do {
		txt[--ptr] = '0' + frq % 10;
		frq /= 10;
		} while (frq > 0);

		while (ptr > 0)
		txt[--ptr] = ' ';

		txt[4]='.';
		txt[5]='0' + (frac / 10);
		txt[6]='0' + frac % 10;

		//freq = 440 * 2^((note-57)/12), where note = 12 * octave /0..7/ + note_in_octave /0..11/

		float note = 12.0 * log(freq/440.0) / LOG2 + 57; //again, long live avrlibc math

		if (note < 0) note = -0.4;
		if (note > 95.0) note = 95.4; //out of scale

		unsigned char rnote = (unsigned char) (note + 0.5); //nearest note
		float dif = note - (float) rnote;

		if(dif < -0.25)
		txt[7]='<';
		else
		txt[7]=' ';
		if(dif < -0.01)
		txt[8]='<';
		else
		txt[8]=' ';
		if(dif > 0.01)
		txt[14]='>';
		else
		txt[14]=' ';
		if(dif > 0.25)
		txt[15]='>';
		else
		txt[15]=' ';

		txt[13] = '0' + rnote / 12;
		rnote %= 12;
		rnote *= 3;
		txt[9] = notes[rnote];
		txt[9] = notes[rnote];
		txt[11] = notes[rnote + 1];
		txt[12] = notes[rnote + 2];

		LCD_clear ();
		LCD_printAt (SND_LINE_FST_CHAR, txt);
		}
		}


		int main() {
		char curr_sample;
		no_of_samples = 0;
		avg = 0;
		ngainchg = FALSE;
		int main (void) {
		count_down_up = 0;

		/* Init LED. */
		LED_init ();
		@@ -370,46 +156,58 @@ int main() {
		LCD_init ();
		startup_LCD ();

		/* Init interrupts and ADC. */
		ADC_init ();
		/* Init input and timer. */
		input_init ();
		timer1_init ();
		sei();

		/* Infinite loop to run program. */
		for (;;) {
		move_cursor ();
		wait_for (500);
		sei ();
		if (size > 0) {
		if(size >= MAX_QUEUE_LEN) {
		/* Signal an error on overflow. */
		toggle_bit (PORT_LED, BIT_LED);
		LCD_printAt (FST_LINE_FST_CHAR, EMPTY_LINE);
		LCD_printAt (SND_LINE_FST_CHAR, "OVERFLOW ERROR");
		/* Wait indefinetely. */
		for(;;);
		}
		/* Disable interrupt for the moment, to avoid races. */
		cli ();
		curr_sample = queue[start];
		start = (start + 1) % MAX_QUEUE_LEN;
		size--;
		/* Reenable interrupts. */
		sei ();
		/* Process current sample. */
		process_sample (curr_sample);
		}
		}

		return 0;
		}

		/*
		* ADC Interrupt Routine.
		*/
		ISR (ADC_vect) {
		if (size < MAX_QUEUE_LEN) {
		/* Add ADC value to the queue in order to be processed. */
		queue[stop] = ADCH;
		stop = (stop + 1) % MAX_QUEUE_LEN;
		size++;
		char buff[10];

		ISR (PCINT1_vect) {
		if ((PINB & (1 << PB7)) == 0) {
		/* If there is a low-high transition */
		count_down_up++;
		}
		}

		/* Timer interrupt. */
		ISR (TIMER1_COMPA_vect) {
		sum += count_down_up;
		count++;

		if (count == 3) {
		refresh_snd_line ();
		toggle_bit (PORT_LED, BIT_LED);
		sum /= count;
		int diff = sum - std_fr[chosen_string];
		char c = '-';
		if (diff > 0) {
		c = '+';
		} else if (diff == 0) {
		c = '0';
		}
		int abs_diff = abs (diff);
		float percent = (float) abs_diff / (std_fr[chosen_string] * 2) * 100;
		int percent_i = (int) percent;
		itoa (percent_i, buff, 10);
		int n = strlen (buff);
		buff[n] = '%';;
		buff[n + 1] = c;
		buff[n + 2] = '\0';
		LCD_printAt (SND_LINE_FST_CHAR, buff);
		LCD_printAt (FST_LINE_FST_CHAR + chosen_string * 3, "");

		count = 0;
		sum = 0;
		}

		count_down_up = 0;
		}

Makefile

+1 −1

File changed.

Contains only whitespace changes.