timer.c

This is full set of procedures used to communicate with any GSM module for SMS sending/receiving (

/*
 *  FILE:
 *     timer.c (rev. 1.1 - 11.05.2007)
 *
 *  PROJECT:
 *     GSM Communication Module
 *
 *  DESCRIPTION:
 *     See "timer.h" for description
 *
*/

#include "types.h"
#include "timer.h"
#include "gsm-link.h"

U8  volatile TMR_SMS;       // Timer for SMS processor (resolution: 0.1 sec)
U8  volatile TMR_GSM;       // Timer for GSM phone response timeout (resolution: 0.1 sec)

U16 TMR_System;             // System Timer (1 ms)
U8  TMR_Slow;               // System slow Timer (0.1 sec)

// Initialize and start timer
void TMR_Init(void) {
    TMR_System=0; TMR_Slow=100;
    TMR_GSM=0;
    TCCR2=0x0E;             // Configure Timer 2: prescaler=256, CTC mode
    OCR2=TMR_Val;           // Configure MAX value for timer 2
    TCNT2=0;                // Clear timer 2 counter
    TIMSK|=0x10;            // Enable timer 2 compare match interrupt
}

// Timer 2 compare match ISR
#pragma vector=TIMER2_COMP_vect
__interrupt void Timer2OutCompare(void) {
    U8 i;
    TMR_System++;
    if (TMR_Slow==0) {
        // Slow timer routine (invoked every 0.1 sec.)
        TMR_Slow=100;
        if (TMR_SMS) TMR_SMS--;
        if (TMR_GSM) {
            TMR_GSM--;
            // If end GSM timeout timer expire
            if (TMR_GSM==0) GSM_EndOfPacket();
        }
    }
    else TMR_Slow--;
}

// Hardware delay (resolution: 1 ms)
void TMR_Delay(U16 delay) {
    __disable_interrupt();
    TMR_System=0;
    __enable_interrupt();
    while(TMR_System<delay);
}