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justinjohney

Posted: Jun 18, 2012 - 01:59 PM

Joined: Jun 04, 2012
Posts: 295
Location: Mumbai,India

im a beginer to avr
what is wrong with this code

Code:

#include <avr/io.h> 

#include <avr/interrupt.h>

#include <util/delay.h>

int adc_result=0;

int ch=0;

int main (void) 

{ 

//set portC as input and enable the pull up resistor 

DDRC=0x00;

PORTC=0xFF;

//set up port D 0-5  as output& C 6,7 as input

DDRD=0x3F;

// Set ADC prescaler to 128 - 125KHz sample rate @ 16MHz 

ADCSRA |= (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);

// Set ADC to Free-Running Mode 

ADCSRB &=~((1<<ADTS2)|(1<<ADTS1)|(1<<ADTS0)) ;  

// Enable ADC 

ADCSRA |= (1 << ADEN);  

// Enable ADC Interrupt

//ADCSRA |= (1 << ADIE);  

// Enable Global Interrupts 

 //sei();  

// Loop Forever 

    while(1)

       { 

      // Set ADC reference to AREF

      // Left adjust ADC result to allow easy 10 bit reading

      //select adc channel 1

      ADMUX=0x00;

         for(ch=0;ch<3;ch++)

          {

             // Start A2D Conversions 

            ADCSRA |= (1 << ADSC);

            //Read the adc result

            adc_result=ADCW;

                _delay_ms(10);

            if(adc_result>970)

            {

               if(ch==0)

               {

                  PORTD1=1;

                  _delay_ms(50);

                     if(adc_result>970)

                        {

                           PORTB4=1;

                        }

               }

               else if(ch==1)

               {

                  PORTD2=1;

                  _delay_ms(50);

                     if(adc_result>970)

                        {

                           PORTB4=1;

                        }

               }

               else(ch==2)

               {

                  PORTD2=1;

                  _delay_ms(50);

                     if(adc_result>970)

                        {

                           PORTB4=1;

                        }

            }

            ADMUX++;

         }

   }

}

theusch

Posted: Jun 18, 2012 - 02:25 PM

Joined: Feb 19, 2001
Posts: 25909
Location: Wisconsin USA

Quote:

what is wrong with this code

What AVR model are you working with?
What do you expect to happen?
What is happening?
How are you testing?
What problem(s) are you encountering?

The entire logic of the program is strange. The value is checked for 970--and then again checked. How can it change?

A conversion is started and the result taken--without waiting for the conversion to complete.

In free-running mode, you can easily be grabbing the result from the "previous" channel.

clawson

Posted: Jun 18, 2012 - 02:34 PM

Joined: Jul 18, 2005
Posts: 62299
Location: (using avr-gcc in) Finchingfield, Essex, England

Code:

             // Start A2D Conversions

            ADCSRA |= (1 << ADSC);

            //Read the adc result

            adc_result=ADCW;

Did we perhaps forget to do something in the middle here? Contrary to popular belief the result in ADCW will not be available just a few cycles after you set the ADSC bit. Try putting a:

Code:

while(ADCSRA & (1<<ADSC)));

between those lines to sit and wait while ADSC remains high - it will return to 0 and hence end the while() loop when the conversion is complete.

Code:

PORTD1=1;

I'd be interested to see the definition of "PORTD1". True, if you use something like Peter Danegger's sbit.h then something like this might be valid syntax but I see no such #include of the necessary .h file.

_________________

theusch

Posted: Jun 18, 2012 - 02:42 PM

Joined: Feb 19, 2001
Posts: 25909
Location: Wisconsin USA

Quote:

Code:
PORTD1=1;

I'd be interested to see the definition of "PORTD1".

lol -- I missed that in my first read-through. Wouldn't you get something like a "not an lvalue" error?

Quote:

Error: C:\AtmelC\TestProgs\M88t.c(15): the expression must be a modifiable lvalue

larryvc

Posted: Jun 18, 2012 - 05:45 PM

Joined: Dec 06, 2007
Posts: 2512
Location: Redmond, WA USA

clawson wrote:

Code:

PORTD1=1;

I'd be interested to see the definition of "PORTD1".

You will find that in .inc files for inclusion in an assembly source though it is equated as a bit number exactly the same as PD1 is. Definitely a non-working piece of code here.

_________________
Larry

Those afraid to embrace the future will quickly fade into the past. - larryvc

clawson

Posted: Jun 18, 2012 - 05:49 PM

Joined: Jul 18, 2005
Posts: 62299
Location: (using avr-gcc in) Finchingfield, Essex, England

Quote:

You will find that in .inc files for inclusion in an assembly source

Two pints of whatever you are smoking. How are .inc files involved in the use of avr-gcc?

_________________

larryvc

Posted: Jun 18, 2012 - 07:09 PM

Joined: Dec 06, 2007
Posts: 2512
Location: Redmond, WA USA

clawson wrote:

Quote:

You will find that in .inc files for inclusion in an assembly source

Two pints of whatever you are smoking. How are .inc files involved in the use of avr-gcc?

They're not, but since you asked, I pointed out where they "are" defined. Wink

_________________
Larry

Those afraid to embrace the future will quickly fade into the past. - larryvc

JohanEkdahl

Posted: Jun 18, 2012 - 09:14 PM

Joined: Mar 27, 2002
Posts: 18560
Location: Lund, Sweden

OT:

Quote:

Two pints of whatever you are smoking.

LOL! A really crap day can always be saved by something like this.

theusch

Posted: Jun 18, 2012 - 10:24 PM

Joined: Feb 19, 2001
Posts: 25909
Location: Wisconsin USA

Quote:

OT:
Quote:
Two pints of whatever you are smoking.

LOL! A really crap day can always be saved by something like this.

Try "I'll have what she's having", from "When Harry Met Sally".
http://www.youtube.com/watch?v=F-bsf2x-aeE
Start at about 1:30.

JohanEkdahl

Posted: Jun 18, 2012 - 10:30 PM

Joined: Mar 27, 2002
Posts: 18560
Location: Lund, Sweden

Quote:

Try "I'll have what she's having", from "When Harry Met Sally".

Seen that a few times, yup.

But this... http://www.youtube.com/watch?v=qJP8_6wKNso (round about 30 seconds). Absolutely priceless!

larryvc

Posted: Jun 18, 2012 - 10:49 PM

Joined: Dec 06, 2007
Posts: 2512
Location: Redmond, WA USA

I just want to know how you two got soooo OT from Johan's previous post. Laughing

_________________
Larry

Those afraid to embrace the future will quickly fade into the past. - larryvc

theusch

Posted: Jun 18, 2012 - 11:15 PM

Joined: Feb 19, 2001
Posts: 25909
Location: Wisconsin USA

It was >>Cliff's fault<< for mixing his metaphors.

No, wait--the root cause was >>you<< -- inserting [the low-level programming technique that shall not be mentioned] into a high-brow C thread.

justinjohney

Posted: Jun 19, 2012 - 05:32 AM

Joined: Jun 04, 2012
Posts: 295
Location: Mumbai,India

theusch wrote

Code:

What AVR model are you working with?

AVR Studio 4, GCC compiler

Code:

What do you expect to happen?

actually i want to convert three analog signal into digtal simultaneously(with max speed) and compare it with threashold and if any one it is greater than the threashold then a led must glow corresponding to that signal.Moreover if the condition stable for a particular time then there must be get an o/p on a port pin at a particular pin.

Code:

What problem(s) are you encountering?

build error,i know the code is not completed

i think now you got it. can you help me?[/code]

larryvc

Posted: Jun 19, 2012 - 06:58 AM

Joined: Dec 06, 2007
Posts: 2512
Location: Redmond, WA USA

Did you read clawson's post two posts ater your first post?

http://www.avrfreaks.net/index.php?name ... 434#966434

What does PORTD1=1; do?

Have you written any code to just blink an LED yet?

_________________
Larry

Those afraid to embrace the future will quickly fade into the past. - larryvc

mtaschl

Posted: Jun 19, 2012 - 08:47 AM

Joined: Aug 21, 2002
Posts: 895
Location: Austria

justinjohney wrote:

theusch wrote

Quote:

What AVR model are you working with?

AVR Studio 4, GCC compiler

Thanks for telling us the tool-chain, but what does this have to do with the AVR model (=the chip on which your program is intended to run)?

_________________
/Martin.

JohanEkdahl

Posted: Jun 19, 2012 - 09:21 AM

Joined: Mar 27, 2002
Posts: 18560
Location: Lund, Sweden

Quote:

That rang a bell. So I digged through earlier threads by the OP, and:

http://www.avrfreaks.net/index.php?name ... 571#962571

http://www.avrfreaks.net/index.php?name ... 310#964310

Hey Justin! Please stay in one thread with your work on these ADC-and-threshold questions.

MODERATOR: Perhaps the other two threads should be locked? [done - clawson]

bobgardner

Posted: Jun 19, 2012 - 12:45 PM

Joined: Sep 04, 2002
Posts: 21258
Location: Orlando Florida

I asked if the signals were AC or DC. You said the signals were 50Hz AC. I assume you want to read the peak or the average amplitude of these signals, which will require either some digital signal processing to determine the peak or average of a group of samples, or a diode and an RC low pass filter to 'catch' the signal for 20ms so the a/d converter can read it. I felt sort of miffed that you didn't mention that you had read my suggestion and understood it.

_________________
Imagecraft compiler user

Last edited by bobgardner on Jun 19, 2012 - 10:11 PM; edited 1 time in total

justinjohney

Posted: Jun 19, 2012 - 01:26 PM

Joined: Jun 04, 2012
Posts: 295
Location: Mumbai,India

atmega168
the following code shows error in avr studio, avr gcc compiler.

Code:

#include <avr/io.h>

#include <stdio.h>  

#include <avr/interrupt.h>

#include <util/delay.h>

//system clock @16MHz

#define F_CPU 16000000 

//Global variable 

int adc_result[2]={0,0,0};

uint8_t ch=0;

/* PORT INIT */

void port_init (void) 

{

//set portB.1 as output

DDRB |=(1<<PB1);

PORTB&=~(1<<PB1);

//set portC0,1,2, as input and enable the pull up resistor 

DDRC &=~(1<<PC0)|~(1<<PC1)|~(1<<PC2);

PORTC |=(1<<PC0)|(1<<PC1)|(1<<PC2);

//set up port D 0-2  as output& D6,7 as input with pull up resistor 

DDRD &=~(1<<PC0)|~(1<<PC1)|~(1<<PC2);

DDRD &=~(1<<PD6)|~(1<<PD7);

PORTD |=(1<<PD6)|(1<<PD6);

}

void init_adc(void)

{

// Set ADC prescaler to 128 - 125KHz sample rate @ 16MHz 

ADCSRA |= (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);

// Set ADC to Free-Running Mode 

//ADCSRB &=~((1<<ADTS2)|(1<<ADTS1)|(1<<ADTS0)) ; 

//select adc channel 0

//ADMUX=ch; 

// Enable ADC Interrupt

ADCSRA |= (1 << ADIE);  

// Enable ADC

ADCSRA |= (1 << ADEN);  

// Enable Global Interrupts 

sei();

//Start first conversion 

ADCSRA |= (1<<ADSC);

}

/* Interrupt service routines */ 

ISR(ADC_vect)

{

//delay  for discarding first conversion result

//_delay_ms(10);

//Read the adc result

   switch(ch)

   {

      case 0:

         {

         adc_result[0]=ADCW;

         if(adc_result[0]>862)

            {

               do

               {

               PORTD|=(1<<PD0);//glow the led corresponding to signal 1

               //Start next  conversion with same channel

               _delay_ms(3);

               ADCSRA |= (1<<ADSC);

               adc_result[0]=ADCW;

                  if(adc_result[0]>887)

                  {

                     do

                     {

                     ADCSRA |= (1<<ADSC);

                     adc_result[0]=ADCW;

                     PORTB|=(1<<PB0);//  o/p drive if the state at adc0 exist for a particular time      

                     }while (adc_result[0]<970)

                  }   

               }while(adc_result[0]<862)

            }

         else if (adc_result[0]<754)

            {

            PORTD|=(1<<PD3);//glow the led corresponding to UV indication

            }

         else

            {

               if(ch<3)

               {

                  ch++;

                  ADMUX=ch;

               }

               else

               {

                  ch=0;

                  ADMUX=ch;

               }

            }

         break;

         }

      case 1:

         {

         adc_result[1]=ADCW;

         if(adc_result[1]>862)

            {

               do

               {

               PORTD|=(1<<PD1);//glow the led corresponding to signal 2

               //Start next  conversion with same channel

               _delay_ms(3);

               ADCSRA |= (1<<ADSC);

               adc_result[0]=ADCW;

                  if(adc_result[0]>887)

                  {

                     do

                     {

                     ADCSRA |= (1<<ADSC);

                     adc_result[0]=ADCW;

                     PORTB|=(1<<PB0);//  o/p drive if the state at adc1 exist for a particular time      

                     }while (adc_result[1]<862)

                  }

               }while(adc_result[1]<862)

            }

         else if(adc_result[1]<754)

            {

            PORTD|=(1<<PD3);//glow the led corresponding to UV indication

            }

         else

            {

               if(ch<2)

               {

                  ch++;

                  ADMUX=ch;

               }

               else

               {

                  ch=0;

                  ADMUX=ch;

               }

            }

         break;

         }

      case 2:

         {

         adc_result[2]=ADCW;

         //Start next  conversion 

         ADCSRA |= (1<<ADSC);

         if(adc_result[2]>862)

            {

               do

               {

               PORTD|=(1<<PD2);//glow the led corresponding to signal 3

               //Start next  conversion with same channel

               _delay_ms(3);

               ADCSRA |= (1<<ADSC);

               adc_result[0]=ADCW;

               if(adc_result[2]>887)

                  {

                     do

                     {

                     ADCSRA |= (1<<ADSC);

                     adc_result[0]=ADCW;

                     PORTB|=(1<<PB0);//  o/p drive if the state at adc2 exist for a particular time      

                     }while (adc_result[2]<862)

                  }

               }while(adc_result[2]<862)

            }

         else if(adc_result[2]<754)

            {

            PORTD|=(1<<PD3);//glow the led corresponding to UV indication

            }

         else

            {

               if(ch<3)

               {

                  ch++;

                  ADMUX=ch;

               }

               else

               {

                  ch=0;

                  ADMUX=ch;

               }

            }

         break;

         }

   }

}

void main() 

{ 

   port_init();

// Loop Forever 

    while(1)

       { 

      ADMUX=ch; 

      init_adc();

      }         

}

clawson

Posted: Jun 19, 2012 - 01:28 PM

Joined: Jul 18, 2005
Posts: 62299
Location: (using avr-gcc in) Finchingfield, Essex, England

Saying what the error is would help as then we wouldn't have to compile it ourselves (I'm not in a position to do so in my current location).

BTW you do know that warnings/errors include both the filename and the line number (test.c:109 is line 109 of test.c) so you should be able to identify the exact line where the error is located.

_________________

mtaschl

Posted: Jun 19, 2012 - 01:40 PM

Joined: Aug 21, 2002
Posts: 895
Location: Austria

Code:

int adc_result[3]={0,0,0};

instead of

Code:

int adc_result[2]={0,0,0};

Code:

DDRC &=~((1<<PC0)|(1<<PC1)|(1<<PC2));

instead of

Code:

DDRC &=~(1<<PC0)|~(1<<PC1)|~(1<<PC2);

(replace on all occurances).

Code:

// Set ADC prescaler to 128 - 125KHz sample rate @ 16MHz 

ADCSRA |= (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);

Are you sure, that you are running on 16 MHz and not on the internal 1 MHz ( 8 MHz / 8 ) as this is default?

Put all stuff from your ISR outside since you do it in polling-mode and all this stuff including the delays should never be done inside an ISR.

I suggest you to read the tutorial on bit-manipulation

_________________
/Martin.

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