mikrokontrollersystemer-prosjekt/prosjekt.X/fan-speed.c

#include "fan-speed.h"
#include "uart.h"

uint16_t timer_period_ms = 1000;
uint16_t fan_speed = 0;
volatile uint16_t fan1_edge_counter = 0;
volatile uint16_t fan2_edge_counter = 0;


void init_TCA0() {
    TCA0.SINGLE.INTCTRL = TCA_SINGLE_OVF_bm ;
    TCA0.SINGLE.CTRLA = TCA_SINGLE_ENABLE_bm | TCA_SINGLE_CLKSEL_DIV1024_gc ; /* Sysclk /1024 */
}

void TCA0_update_period(uint16_t period_ms) {
    float period_s = period_ms / 1E3; // Convert the ms to s
    float frequency = 1/ period_s; // convert the period to a frequency
    float perbuf_val = frequency * F_CPU / 1024; // F_IQR * F_CPU / TCA_prescaler
    TCA0.SINGLE.PERBUF = (uint16_t)perbuf_val;
    timer_period_ms = period_ms;
}

// COUNTINGS / TIME = FREQUENCY
// FREQ / 2 = GIVES ACTUAL FREQ
// FREQ * SEC-IN-A-MINUTE(60) / FAN-BLADES
uint16_t RPM_calculation(uint16_t edge_counter, uint16_t time_ms) {
    fan_speed = (edge_counter / (float)((float)time_ms/1000.0) );
    fan_speed = fan_speed/2; 
    fan_speed = fan_speed * 60/5;
    edge_counter = 0;
    return fan_speed;
}


void init_fan_gpio() {
    // CONFIGURE PINS AS ANALOG INPUTS
    
    // PIN FOR FAN 1
    PORTD.DIRSET &= ~PIN6_bm;
    PORTD.PIN6CTRL &= ~ PORT_ISC_gm;
    PORTD.PIN6CTRL = PORT_ISC_INPUT_DISABLE_gc;
    
    // PIN FOR FAN 2
    PORTD.DIRSET &= ~PIN4_bm;
    PORTD.PIN4CTRL &= ~ PORT_ISC_gm ;
    PORTD.PIN4CTRL = PORT_ISC_INPUT_DISABLE_gc;
    
    // PIN FOR REFRENCE
    PORTD.DIRSET &= PIN7_bm;
    PORTD.PIN7CTRL &= ~ PORT_ISC_gm ;
    PORTD.PIN7CTRL = PORT_ISC_INPUT_DISABLE_gc;
}

void init_AC0(){ 
    //Wincontroll disabled
    AC0.CTRLB = 0x00;
    
    //SELECT POSITIVE AND NEGATIVE INPUTS FOR COMPARRISON
    // FAN USE PD6 COMPARE WITH PD3
    AC0.MUXCTRL = AC_MUXPOS_AINP3_gc | AC_MUXNEG_AINN2_gc;
    
    // ENABLE AC BY WRITING 1 TO ENABLE BIT IN ACN.CTRLA
    AC0.CTRLA = AC_ENABLE_bm | AC_INTMODE_NORMAL_POSEDGE_gc | AC_OUTEN_bm;
    
    // TURN ON INTERUPT
    AC0.INTCTRL = 0x01; 
}


void init_AC1(){    
    //Wincontroll disabled
    AC1.CTRLB = 0x00;
    
    //SELECT POSITIVE AND NEGATIVE INPUTS FOR COMPARRISON
    // FAN USE PD4, COMPARE WITH PD3
    AC1.MUXCTRL = AC_MUXPOS_AINP2_gc | AC_MUXNEG_AINN2_gc;
    
    // ENABLE AC BY WRITING 1 TO ENABLE BIT IN ACN.CTRLA
    AC1.CTRLA = AC_ENABLE_bm | AC_INTMODE_NORMAL_POSEDGE_gc | AC_OUTEN_bm;
    
    // TURN ON INTERUPT
    AC1.INTCTRL = 0x01; 
}


ISR(AC0_AC_vect){ // AC0 vec flag 
    cli();
    fan1_edge_counter++;
    AC0.STATUS |= 0x10; //CMP flag to 0
    sei();
}


ISR(AC1_AC_vect){ // AC1 vec flag 
    cli();
    fan2_edge_counter++;
    AC1.STATUS |= 0x10; //CMP flag to 0
    sei();
}

// TIMER INTERUPT
ISR (TCA0_OVF_vect) {
    cli();
    
    // Increment the index, or reset if it is at the top
    if (fan1_history_index < 512) {
        fan1_history_index++;
    } else {
        fan1_history_index = 0;
    }
    
    if (fan2_history_index < 512) {
        fan2_history_index++;
    } else {
        fan2_history_index = 0;
    }
    
    // Calculate the fanspeed
    fan1_history[fan1_history_index] = RPM_calculation(fan1_edge_counter, timer_period_ms);
    fan2_history[fan2_history_index] = RPM_calculation(fan2_edge_counter, timer_period_ms);
        
    // Reset the edge counter
    fan1_edge_counter = 0;
    fan2_edge_counter = 0;
    TCA0.SINGLE.INTFLAGS = TCA_SINGLE_OVF_bm ;
    sei();
}