/* * XARIAS carputer project * * Copyright (c) 2007 by Roman Pszonczenko xtensa <_at_> gmail * *   This program is free software; you can redistribute it and/or modify *   it under the terms of the GNU General Public License as published by *   the Free Software Foundation; either version 3 of the License, or *   (at your option) any later version. * *   This program 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 General Public License for more details. * *   You should have received a copy of the GNU General Public License *   along with this program; if not, write to the Free Software *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA */#include "defines.h"#include <ctype.h>#include <stdint.h>#include <stdio.h>#include <avr/io.h>#include <avr/pgmspace.h>#include <util/delay.h>#include <util/twi.h>#include <avr/interrupt.h>#include "lcd.h"#define PIN_INJ   PIND&_BV(3)#define PORT_INJ  PORTD|_BV(3)/* * Injector flow constant in ml/min * For Toyota Corolla 1,3 4EFE it's 136 - 176 * For Toyota Corolla 1,6 4AFE it's 160 - 200 */#define INJ_FLOW 156/* * Number of ticks per one kilometer */#define SPEED_TICKS 2548FILE lcd_str = FDEV_SETUP_STREAM(lcd_putchar, NULL, _FDEV_SETUP_WRITE);uint32_t passed_seconds=0, tcnt0_overs=0, passed_speed_ticks=0;uint16_t clock_ticks=0, inj_ticks=0, tcnt0_overs_sec=0;void error(char *msg){	stderr = &lcd_str;	lcd_locate(2,1);	fprintf(stderr,"ERR: %s",msg);}/* * This function sends one byte through TWI bus. * It returns 0 on success and 1 if failed. */uint8_t twi_write_data(uint8_t data){	TWDR = data;	TWCR = _BV(TWINT) | _BV(TWEN);	/*	 * waiting for TWINT flag set	 */	while (!(TWCR & _BV(TWINT)));	if ( TW_STATUS != TW_MT_DATA_ACK) 	{		error("MT_DATA_ACK cmd");		return 1;	}	return 0;}/* * Do all the startup-time peripheral initializations. */static void ioinit(void){	lcd_init();	/*	 * SCL = CPU_Freq / ( 16 + 2 * TWBR * 4^TWPS )	 */	TWBR = 98; // with prescaller = 1 gives us 100kHz TWI bus	TWSR = 0;  // prescaller = 1	/*	 * enablibg TWI and sending START condition	 */	TWCR = _BV(TWINT)|_BV(TWSTA)|_BV(TWEN);	/*	 * waiting for TWINT flag set	 */	while (!(TWCR & _BV(TWINT)));		if ( TW_STATUS != TW_START) error("TWI START cmd");	/*	 * writing SLA_W and device address 1101 000	 */	TWDR = TW_WRITE | 0xD0; 	TWCR = _BV(TWINT) | _BV(TWEN);	/*	 * waiting for TWINT flag set	 */	while (!(TWCR & _BV(TWINT)));	if ( TW_STATUS != TW_MT_SLA_ACK) error("MT_SLA_ACK cmd");	/*	 * writing address start 0	 */	twi_write_data(0);	twi_write_data(0);	twi_write_data(0);	twi_write_data(0);	twi_write_data(0);	twi_write_data(0);	twi_write_data(0);	twi_write_data(0);	/*	 * writing control register	 * turning on output (bit 7) and setting 32,768 kHz (bits 0 and 1)	 */	twi_write_data(_BV(4)|_BV(0)|_BV(1));	TWCR = _BV(TWINT)|_BV(TWEN)|_BV(TWSTO);	/*	 * Enable external interrupt 0	 */	GICR = _BV(INT0);	/*	 * Falling edge will generate interrupt 0	 */	MCUCR |= _BV(1);	/*	 * enable pull-up resistors for ports D2 and D3	 */	PORTD |= _BV(2) | _BV(3);	/*	 * enable all interrupts	 */	sei();	/*	 * external clock source for Timer0, clock on falling edge	 */	TCCR0 |= _BV(2) | _BV(1);	/*	 * enable Timer0 overflow interrupt	 */	TIMSK |= _BV(0);}/* * This function return fuel consumption in l/h * 1000 * We assume that fuel consumption is not greater than 65.536 l/h * Although l_inj_ticks is uint64_t, it cannot be greater than * xxxxxx and  */uint16_t calc_fuel_h(uint64_t l_inj_ticks, uint32_t l_seconds){	return (uint16_t)((l_inj_ticks*INJ_FLOW*15)/((uint64_t)2048*l_seconds));}uint16_t calc_fuel_100(uint16_t l_fuel_h, uint64_t l_speed_ticks, uint32_t l_seconds){	return (uint16_t)(((uint64_t)l_fuel_h*SPEED_TICKS*l_seconds)/(l_speed_ticks*36));}uint16_t calc_speed_m(uint64_t l_speed_ticks, uint32_t l_seconds){	return (uint16_t)(l_speed_ticks*1000/(SPEED_TICKS*l_seconds));}uint32_t power(uint32_t x, uint8_t y){	uint8_t i;	uint32_t retval=1;	for(i=0;i<y;i++,retval*=x);	return retval;}/* * Cuts last p digits of the value */#define CUT(val,mult) ((uint16_t)((val)/power(10,(uint8_t)mult)))/*  * The most calculations in this program made on integer values.  * Floating point precision is achieved by doing calculations on  * values multiplied with 10^x, where i x is precision. For example  * if we want to write 2.345 with precision of 3 digits after  * floating point, we will use 2345, as it is equal to 2.345*10^3 * Recalculation is done just before displayng the values. * The next three macros are provided to made such calculations. * * Parameters: *    <val>   - value on which calculations are made *    <mult>  - multiplier  *    <prec>  - precision of the calculations; shoud be less *              or equal then multiplier * * ROUND macro just do the rounding to <prec> digits after * imaginable point. Be aware that it does not truncate the rest  * digits * * uint32_t gives us 4294967 km 296 m of maximium pass */#define ROUND(val,mult,prec) ((uint32_t)(val+5*power(10,(uint8_t)mult-prec-1)))/* * This macro just truncates digits after the floating point, so it * only left integer part before. */#define ROUND1(val,mult,prec) ((uint16_t)CUT(ROUND(val,mult,prec),mult))/* * And the following macro truncate digits before floating point, * so it only left floating part with the specified precision. */#define ROUND2(val,mult,prec) (uint16_t)(CUT(ROUND(val,mult,prec)-CUT(ROUND(val,mult,prec),mult)*power(10,(uint8_t)mult),mult-prec))int main(){	stderr = &lcd_str;	ioinit();	return 0;}SIGNAL(SIG_INTERRUPT0){	static uint64_t passed_inj_ticks=0;	uint8_t pin_inj_state=PIN_INJ;	if(!pin_inj_state) inj_ticks++;	if(!clock_ticks)	{		uint16_t m_speed_m, m_speed_km, avg_speed_m, avg_speed_km;		uint16_t m_fuel_h, m_fuel_100, avg_fuel_h, avg_fuel_100, speed_ticks;		uint32_t passed_distance;		uint8_t  tcnt0;				tcnt0=TCNT0;		TCNT0=0;		tcnt0_overs_sec=0;		speed_ticks=tcnt0_overs_sec*256+tcnt0;		passed_speed_ticks += speed_ticks;		passed_inj_ticks += inj_ticks;		passed_distance=passed_speed_ticks*1000/SPEED_TICKS;		m_fuel_h     = calc_fuel_h(inj_ticks,1);		m_fuel_100   = calc_fuel_100(m_fuel_h,speed_ticks,1);		avg_fuel_h   = calc_fuel_h(passed_inj_ticks,passed_seconds);		avg_fuel_100 = calc_fuel_100(avg_fuel_h,passed_speed_ticks,passed_seconds);		m_speed_m    = calc_speed_m(speed_ticks,1);		m_speed_km   = m_speed_m * 36 / 10;		avg_speed_m  = calc_speed_m(passed_speed_ticks,passed_seconds);		avg_speed_km = avg_speed_m * 36 / 10;		// printing speed in km/h and m/s		lcd_locate(1,1);		fprintf(stderr, "%3u km/h  %3u m/s",m_speed_km,m_speed_m);		// printing fuel consumption		lcd_locate(2,1);		fprintf(stderr, " %3u.%u l/100km %2u.%u l/h",ROUND1(m_fuel_100,3,1),ROUND2(m_fuel_100,3,1),ROUND1(m_fuel_h,3,1),ROUND2(m_fuel_h,3,1));		// temporarily: checking for error		if(ROUND2(m_fuel_100,3,1)>9) { lcd_locate(1,1); fprintf(stderr,"%u",m_fuel_100); while(1);}				// avarage speed and fuel consumption		lcd_locate(3,1);		fprintf(stderr, "%3u km/h %3u.%u l/100",avg_speed_km,ROUND1(avg_fuel_100,3,1),ROUND2(avg_fuel_100,3,1));				// printing journey time		lcd_locate(4,1);		fprintf(stderr,"%02u:%02u:%02u", (uint8_t)(passed_seconds/3600),(uint8_t)((passed_seconds%3600)/60),(uint8_t)(passed_seconds%60));		// printing passed dist		lcd_locate(4,10);		fprintf(stderr, "%4u.%03u km",ROUND1(passed_distance,3,3),ROUND2(passed_distance,3,3));						passed_seconds++;		inj_ticks=0;	}	clock_ticks++;	if(clock_ticks==32768)	{		clock_ticks=0;	}}SIGNAL(SIG_OVERFLOW0){	tcnt0_overs++;	tcnt0_overs_sec++;}