main.c

AVR DRAGON的仿真版配套源程序,包括定时器,LCD驱动,按键处理,AD转换等等.对AVR初学者甚为有用

//*****************************************************************************
//  File........: main.c
//  Author(s)...: ATMEL Norway
//  Target(s)...: ATmega169 in Butterfly or STK502
//  Compiler....: AVR GCC 20060421
//  Description.: Main loop and initialization
//  Revisions...: 1.1
//  YYYYMMDD - VER. - COMMENT                                       - SIGN.
//  20030326 - 1.0  - Created                                       - AR
//	20060829 - 1.1  - Ported to AVR GCC                             - TMF, OL
//*****************************************************************************

//  Include files
#include <avr/interrupt.h>
#include "Main.h"

/******************************************************************************************
*   Function name:  main
*   returns:        None
*   parameters:     None
*   Purpose:        Main function which contains the endless main loop
******************************************************************************************/
int main(void)
{

    //Variables
    unsigned int i;
    int ADC_temp;
    int adc = 0;

    //Initialization
    ADMUX = 2;    // external AREF and ADCx
    ADCSRA = (1<<ADEN) | (1<<ADPS1) | (1<<ADPS0);    // set ADC prescaler to , 1MHz / 8 = 125kHz

	while(1)
	{

    // To save power, the voltage over the LDR and the NTC is turned off when not used
    // This is done by controlling the voltage from a I/O-pin (PORTF3)

    sbi(PORTF, PORTF3);     // Enable the VCP (VC-peripheral)
    sbi(DDRF, PORTF3);

    sbi(ADCSRA, ADEN);     // Enable the ADC

    //do a dummy readout first
    ADCSRA |= (1<<ADSC);        // do single conversion
    while(!(ADCSRA & 0x10));    // wait for conversion done, ADIF flag active

    for(i=0;i<32;i++)            // do the ADC conversion 8 times for better accuracy
    {
        ADCSRA |= (1<<ADSC);        // do single conversion
        while(!(ADCSRA & 0x10));    // wait for conversion done, ADIF flag active

        ADC_temp = ADCL;            // read out ADCL register
        ADC_temp += (ADCH << 8);    // read out ADCH register

        adc += ADC_temp;      // accumulate result (32 samples) for later averaging
    }

    adc = adc >> 5;     // average the 8 samples

    cbi(PORTF, PORTF3);     // disable the VCP
    cbi(DDRF, PORTF3);

    cbi(ADCSRA, ADEN);      // disable the ADC

    }
}