Hi All,

I'm currently working through the tutorial, and I decided to do a small side track to test out my programming skills thus far. My goal is a simple program, which will light up one of three LEDs depending on the temperature being read by the temperature sensor. It's a good chance for me to utilize what I've learned from both projects to create a new code.

Temp LED combos are as followed:

<75 - Green between 75 and 83 - Yellow

83 - Blinking Red

Here's my code:

/*
 *  LED_Temp_Sense.c *  
 *
 *  Created byon 2/10/12.
 *  Copyright 20. All rights reserved.
 *
 */

#define F_CPU 14745600

#include <stdio.h>
#include <math.h>

#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <inttypes.h>

#include "../libnerdkits/delay.h"
#include "../libnerdkits/delay.h"  //expected headers from both Blink and Temp Sense//

void adc_init(){
    //startup for ADC//

    ADMUX = 0
    ADCSRA = (1<<ADEN) | (1<<ADPS2) | (1<<ADPS1) | (1<<ADPS0);//setting bits in a registry for the ADC//
    ADCSRA |= (1<<ADSC); //start up the ADC//
}

unint16_t adc_read(){
    //meant to stop the ADC from continuing while processing something//
    while(ADCSRA & (1<<ADSC)){
    }

    unint16_t result = ADCL;
    unint16_t temp = ADCH;
    results = results + (temp<<8);

    ADCSRA |= (1<<ADSC);

    return result;
}

double sampleToFahrenheit(uint16_t sample){
    return sample*(5000.0/1024.0/10.0);
}

#define GREEN 75 //Upper temp limit for green LED//
#define RED 83 //lower temp limit for red LED//

int main(){
    //start the Analog to Digital Converter//
    adc_init();

    //Turn the three LEDS to output//
    DDRC |= (1<<PC4);
    DDRC |= (1<<PC3);
    DDRC |= (1<<PC2);

    //holder variable for temp data//
    unit16_t last_sample = 0;
    double this_temp;
    double temp_avg;
    unint8_t i;

    while(1){
        //take 100 samples and average//
        temp_avg = 0.0;
        for(i=0;i<100; i++){
            last_sample = adc_read(); //read from the adc as definded in the funct above//
            this_temp = sampleToFahrenheit(last_sample);

            //add to average//
            temp_avg = temp_avg + this_temp/100.0;
        }

        if(temp_avg <= GREEN){
            PORTC |= (1<<PC4); //75C or below, green led on..
        }
        if(temp_avg > GREEN && <=RED){
            PORTC |= (1<<PC3) //between 75 and 83, yellow on//
        }
        if(temp_avg > RED){
            PORTC |= (1<<PC2);
            delay_ms(500);
            PORTC &= ~(1<<PC2);
            delay_ms;
        }
    }

    return 0;
}

I think its pretty solid, but I can't get it to work. I think part of the problem is my program not reading prior headers, since I cut and pasted or manually typed them in from another code. The errors I get come from compiling, and usually are stating that functions that should be defined by the headers aren't. How do I get it so I can load from the headers?

I'm not looking for someone to rewrite my code fyi, it's there incase I'm doing something stupid. I'd rather suggestions and advice than a solution.

Thanks in advanced. -TUO

Hi TUO -

There could be a few things going on here. First, just make sure the "libnerdkits" folder is in the same parent folder as your project folder. Second, you listed delay.h twice, and I don't think that would be a problem unless you meant to add some other header file. Third, on line 88 above you call "delay_ms" with no argument. The compiler won't like that. On an unrelated matter, on line 81 you have:

 if(temp_avg > GREEN && <=RED){

I don't know for certain if this works as intended. I would go with:

if((temp_avg > GREEN) && (temp_avg <= RED)){

Just to be safe.

Hi TUO,

Could you go into a bit more explanation of what isn't working? Not compiling? Or is it just not behaving as you expected?

Figured it out!

Stupid syntax issues, such as trying to make unint_16 variables instead of the correct uint_16.

Have it loaded, but it doesn't seem to be working... All the LEDs are on...

Back to the drawing board!

Thank to you two for the help. PCbolt I took your advice, much better line of code IMO.

Is there anyway to edit my first post? I hate how wide it is.