/* * Name: vreg.c * Project: AVR-Doper * Author: Christian Starkjohann <cs@obdev.at> * Creation Date: 2006-07-04 * Tabsize: 4 * Copyright: (c) 2006 by Christian Starkjohann, all rights reserved. * License: Proprietary, see documentation. * Revision: $Id: vreg.c 223 2006-07-18 09:28:13Z cs $ */#include <avr/io.h>#include <avr/interrupt.h>#include "vreg.h"#include "stk500protocol.h" /* for stkParam */#define VREG_REF        (uint)((2.06 / 2.56) * 1024)#define CHANNEL_VREG    0#define CHANNEL_TARGET  1#define REFERENCE_BITS  UTIL_BIN8(1100, 0000)#define PWM_RANGE   (1 << 9)#define PWM_CENTER  (PWM_RANGE * 7 / 12)#define DIVIDER (uchar)(22 * 1024 / ((33 + 22) * 25.6)) /* is coincidentally == 16 *//* The divider above normalizes the ADC value to 10 * vTarget */UTIL_INTERRUPT(SIG_ADC) /* run with global interrupt enable */{uint    value = ADC;uchar   muxVal = ADMUX & 0xf;    if(muxVal == CHANNEL_VREG){        int x = PWM_CENTER + ((VREG_REF - value) * 32);        if(x <= 0){            x = 1;        }else if(x > PWM_RANGE - (PWM_RANGE / 5)){            x = PWM_RANGE - (PWM_RANGE / 5);        }        OCR1A = x;        ADMUX = REFERENCE_BITS | CHANNEL_TARGET;    }else{  /* must be CHANNEL_TARGET */        /* Since divider is coincidentally a power of 2, do the division here         * in the interrupt. Otherwise create an accessor function which is         * called when reading the parameter.         */        stkParam.s.vTarget = (value + DIVIDER/2) / DIVIDER;        ADMUX = REFERENCE_BITS | CHANNEL_VREG;    }    ADCSRA |= 1 << ADSC;    /* start next conversion */    }void    vregInit(void){    ADMUX = REFERENCE_BITS | CHANNEL_VREG;    ADCSRA = UTIL_BIN8(1000, 1101); /* enable ADC, enable interrupt, prescaler=32 */    ADCSRA |= 1 << ADSC;    /* start conversion */}