code error

[Adam2014]

hi
i upload a frequency meter code & schematic
but there is an error in measurement ...
for example if i apply an square wave with 5000Hz ,,, LCD display it about 40khz !!!
what is the error ?

 

[Ian Rogers]

freq = dur + i*65536; /* calculate the frequency as in previous equation */

dur and i are declared as int's..... overflow!!!

Cast to longs or declare them as longs...

 

[Adam2014]

thanks
I'll try again

 

[Adam2014]

when i rebuild the the code and restart compile
i see this message "Linker error: the program has no 'main' function"
and proteus can't work with new edit !!!

 

[Ian Rogers]

Post your corrections...

Changing an int to a long can't stop compilation...

 

[Adam2014]

Hi
thanks Ian Rogers
i solve the problem
i have a questions !
Q1) i need to build a bottom to make a force calibration when i press it .
how i can do it in my code ?
the main idea i want to do is "re execute the calibration subroutine" when there is an interrupt from calibration bottom

Q2) how i can monitor the pin state depending on the external switch state ..
i mean how i can know the pin is High/Low using atmega16 & c code

 

[Ian Rogers]

I normally use a button to give a low to the micro pin ( pulled up internally ) then poll the pin for changes..
If you write a small function that can be called from your super loop, that will analyze a range of pins to report a button press. Then you can act on this report...

ie something like this...

int keyhit()
   {
   if(!PIN1) return 1;
   if(!PIN2) return 2;
   return 0;
   }

You will need a debounce.... I use a 200mS delay to debounce..

int keyhit()
   {
   int key=0;
   if(!PIN1) key += 1;
   if(!PIN2) key += 2;
   if(key) delayMs(200);
   return key
   }

 

[Adam2014]

thanks
i define a bottom ca=PORTD.0; // do a forced calibration
how i can make a forced calibration at any time if (ca=High) ,,, even if the Micro controller do another task

 

[Ian Rogers]

When you say "bottom" I was assuming "Button"

If you poll a button each cycle of a super loop its usually fast enough not to miss a press.. However... If you need to you can implement an interrupt to take care of the button press..... If you have capture compare CCP module.. you can detect a single button press and have automatic noise rejection as you can program the module to ensure the key is pressed for a minimum time before registering it..

 

[Adam2014]

Hi
I use code vision avr to program my micro controller atmega16a
when i run the program it still work with the internal oscillation 1MHZ even if i set timer with external clock 16Mhz
" AVR Core Clock frequency: 16.000000 MHz "
so that the value showed is multiple by 16
what the solution to have the real value ?
i try CKSEL=0xf; but with that instruction there is a syntax error

 

[kubeek]

If I remeber correctly the clock settings for the ATmega series are done in fuses, not in code. You need to set this in your programming tool.

 

[Adam2014]

HI
what the problems with my code to display capacitor value ?
because it display the value on all 16 digits LCD Screen ???

//-----------disply Capacitor function --------------------//
float dis_capacitor(unsigned long int c)

{

float cf;
lcd_clear();
lcd_putsf("Capacitor=");
lcd_gotoxy(0,1);
if(c>=0.000001)
{
cf=(float)c*1000000;
ftoa(cf,3, buffer);
lcd_puts(buffer);
lcd_putsf("uF");
}
else if (c>=0.000000001)
{
cxxf=(float)c*1000000000;
ftoa(cf,3, buffer);
lcd_puts(buffer);
lcd_putsf("nF");
}
else
{
ltoa(cf, buffer);
lcd_puts(buffer);
lcd_putsf("pF");
}
delay_ms(3000);
return 0;
lcd_clear();
lcd_gotoxy(0,0);
}

 

[kubeek]

If c is an int, then it will be allways true, unless c is zero. Not sure about the rest.

 

[Adam2014]

HI
when i run the program it take long time to execute
the attached image show the MCU set ,,, what is the problem?

 

[Ian Rogers]

When you "run" your simulation... go into debug mode and see what's causing the slow down....

Have you managed a clean compile??? Otherwise the hex file is never updated...

Step through the program and keep an eye on the "warnings" in the status bar...

 

[Adam2014]

Hi
when i run LC meter the LCD display an initial value with out any DUT (device under test)
How i can edit my code to subtract it from the reading thus LCD display an initial value 0.000 ?

 

[Ian Rogers]

You need to "Map" your input to your LCD output.... If you google you will find examples of mapping.

Mapping...
Display_Value = (((Read_Value - Read_Value_zero_figure) * Displayed_Value_span_figure ) / Read_Value_Span_figure) - Display_Value_Zero_figure....

 

[Adam2014]

thanks Ian Rogers
I'm working now with ADC ...
i want to convert voltage from analog signal to digital and then store it in parameter Vo
where the MCU store its digital value that equal Vo

 

[Ian Rogers]

WHY ARE YOU SHOUTING!!!

I'm not sure what you mean... If you create a variable to hold the result... You need to fetch the value stored in the result register... I can't remember it's name on the AVR chips... The "Map" function should resemble my example above..

 

[Adam2014]

SHOUTING !!!
in my circuit design x=f(V0) ,,, so i want to measure voltage using ADC and then calculate x