/*================================================================================================
 
 CMtec BOSCH_SpeedControlUnit			copyright 2008			  	          v1.0 (2008-08-07)
 
 Name: Christoffer Martinsson
 E-mail: cm@cmtec.se 

 Uses:
 PB1 = PWM output
 PB2 = Sensor input
	
================================================================================================*/

#include <avr/delay.h>
#include <string.h>
#include <inttypes.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/signal.h>
#include <avr/eeprom.h>


 
/*================================================================================================
 Functions
================================================================================================*/
/*------------------------------------------------------------------------------------------------
 initIO
 
 Description: Initialise I/O
 Input: -
 Output: -
------------------------------------------------------------------------------------------------*/
void initIO (void){

	/* Start PLL */
	PLLCSR = (1<<PLLE);
	loop_until_bit_is_set(PLLCSR, PLOCK);
	PLLCSR |= (1<<PCKE);
	
	/* Direction settings for port B */
	DDRB = (1<<PB1);
	
	/* Timer/PWM settings */
	OCR1A = 0;		// PWM value = 0
	OCR1C = 255;	// ~62kHz
	TCCR1 = (1<<PWM1A)|(1<<COM1A0)|(1<<COM1A1)|(1<<CS11)|(1<<CS10);
		
	/* ADC settings */
	DIDR0 = (1<<ADC1D);
	ADMUX = (1<<ADLAR)|(1<<MUX0);
	ADCSRA = (1<<ADEN);
	
}
/*------------------------------------------------------------------------------------------------
 readSensor
 
 Description: Reading value from distance-sensor
 Input: -
 Output: -
------------------------------------------------------------------------------------------------*/
unsigned char readSensor (void){
	
	ADCSRA |= (1<<ADSC);
	loop_until_bit_is_clear(ADCSRA,ADSC);
	return ADCH;
	
}

/*------------------------------------------------------------------------------------------------
 setPWM
 
 Description: Set PMW output
 Input: -
 Output: -
------------------------------------------------------------------------------------------------*/
void setPWM (unsigned char pwmValue){

	if(pwmValue < 255 && pwmValue > 70) 
	{
		pwmValue = pwmValue - 70;
		OCR1A = pwmValue;
	}
	else if(pwmValue <= 70)
	{
		OCR1A = 0;
	}
	else
	{
		OCR1A = pwmValue;
	}
	
}

/*================================================================================================
 Main
================================================================================================*/
int main (void){
	
	unsigned char tmp = 0;

	cli();					// Disable global interrupt  
	
	initIO();
	
	sei();					// Enable global interrupt
	

	while(1){	

		setPWM(readSensor());
	}
	
	
    return (0);
}
/*================================================================================================
 End
================================================================================================*/