pic programming by micro C - Electronic Circuits Projects Diagrams Free

girgis adly · 25th April 2009, 01:20 PM

Dear all iam girgis adly in 4th year electrical faculty of engineer I try to write a program for pic18f452 firing the mosfets of the multilevel inverter at a certain time by a certain sequence and the frequency of the output equal 50 HZ I write the program using (microC) language
void main()
{
TRISB=0;
LOOP:
PORTB=0;
delay_ms(.3355);
PORTB=0B00100110;
delay_ms(2.717);
PORTB=0B00100101;
delay_ms(3.889);
PORTB=0B00100110;
delay_ms(2.667);
PORTB=0;
delay_ms(0.777);
PORTB=0B00011010;
delay_ms(2.667);
PORTB=0B00011001;
delay_ms(3.889);
PORTB=0B00011010;
delay_ms(2.667);
PORTB=0;
delay_ms(0.388);
goto loop;
}

but the compiler found this errors

Internal error line 8
';'expected but delay_ms is found line7
Integral constant expected line6
Syntax error :expected ')'but found ';' line7

I don’t know how to re write the program without errors and without changing the time it will be grateful if any one help me

thanks

eng1 · 25th April 2009, 01:45 PM

Quote:

Originally Posted by girgis adly

Dear all iam girgis adly in 4th year electrical faculty of engineer I try to write a program for pic18f452 firing the mosfets of the multilevel inverter at a certain time by a certain sequence and the frequency of the output equal 50 HZ I write the program using (microC) language
void main()
{
TRISB=0;
LOOP:
PORTB=0;
delay_ms(.3355);
PORTB=0B00100110;
delay_ms(2.717);
PORTB=0B00100101;
delay_ms(3.889);
PORTB=0B00100110;
delay_ms(2.667);
PORTB=0;
delay_ms(0.777);
PORTB=0B00011010;
delay_ms(2.667);
PORTB=0B00011001;
delay_ms(3.889);
PORTB=0B00011010;
delay_ms(2.667);
PORTB=0;
delay_ms(0.388);
goto loop;
}

but the compiler found this errors

Internal error line 8
';'expected but delay_ms is found line7
Integral constant expected line6
Syntax error :expected ')'but found ';' line7

I don’t know how to re write the program without errors and without changing the time it will be grateful if any one help me

thanks

Use a while instruction to generate an end-less loop in C:

Code:

void main()
{
  TRISB=0;
 
  while(1){
 
    // code inside this while loop repeats indefinitely
 
    PORTB=0;
    delay_ms(.3355);
    PORTB=0B00100110;
    delay_ms(2.717);
    PORTB=0B00100101;
    delay_ms(3.889);
    PORTB=0B00100110;
    delay_ms(2.667);
    PORTB=0;
    delay_ms(0.777);
    PORTB=0B00011010;
    delay_ms(2.667);
    PORTB=0B00011001;
    delay_ms(3.889);
    PORTB=0B00011010;
   delay_ms(2.667);
   PORTB=0;
   delay_ms(0.388);
   }
 
// ...

However, I think you have to pass an integer to the mikroC function 'delay_mS'. If you need to wait for fractions of a ms, you could use the function 'delay_us'.

Quote:

delay_ms(.3355);

Delaying fractions of a us can be done including NOP's, if the PIC is running at high frequency (f>4 MHz) but the delay must be an integer multiple of 4/f.
To generate precise delays you should check the assembly code generated by your compiler and do simulations with breakpoints.

girgis adly · 26th April 2009, 01:23 PM

are you mean write
delay _us(335);

eng1 · 26th April 2009, 03:00 PM

Quote:

Originally Posted by girgis adly

are you mean write
delay _us(335);

Yes, this call to delay_us() will delay for 335 us.

delay_us(3889) will delay for 3.889 ms and so on.

As I said, you should check the asm code generated by the compiler and do simulations to verify that the delay will be exactly what you expect.

girgis adly · 28th April 2009, 02:37 PM

thanks eng1 i try this and this is the right code
void main()
{
TRISB=0;
LOOP:
PORTB=0;
Delay_us(337);
PORTB=0B00100110;
Delay_us(2717);
PORTB=0B00100101;
delay_us(3889);
PORTB=0B00100110;
delay_us(2667);
PORTB=0;
delay_us(777);
PORTB=0B00011010;
delay_us(2667);
PORTB=0B00011001;
delay_us(3889);
PORTB=0B00011010;
delay_us(2667);
PORTB=0;
delay_us(388);
goto loop;
}

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25th April 2009, 01:20 PM	#1
girgis adly	pic programming by micro C Dear all iam girgis adly in 4th year electrical faculty of engineer I try to write a program for pic18f452 firing the mosfets of the multilevel inverter at a certain time by a certain sequence and the frequency of the output equal 50 HZ I write the program using (microC) language void main() { TRISB=0; LOOP: PORTB=0; delay_ms(.3355); PORTB=0B00100110; delay_ms(2.717); PORTB=0B00100101; delay_ms(3.889); PORTB=0B00100110; delay_ms(2.667); PORTB=0; delay_ms(0.777); PORTB=0B00011010; delay_ms(2.667); PORTB=0B00011001; delay_ms(3.889); PORTB=0B00011010; delay_ms(2.667); PORTB=0; delay_ms(0.388); goto loop; } but the compiler found this errors Internal error line 8 ';'expected but delay_ms is found line7 Integral constant expected line6 Syntax error :expected ')'but found ';' line7 I don’t know how to re write the program without errors and without changing the time it will be grateful if any one help me thanks

26th April 2009, 01:23 PM	#3
girgis adly	are you mean write delay _us(335);

28th April 2009, 02:37 PM	#5
girgis adly	thanks this is write thanks eng1 i try this and this is the right code void main() { TRISB=0; LOOP: PORTB=0; Delay_us(337); PORTB=0B00100110; Delay_us(2717); PORTB=0B00100101; delay_us(3889); PORTB=0B00100110; delay_us(2667); PORTB=0; delay_us(777); PORTB=0B00011010; delay_us(2667); PORTB=0B00011001; delay_us(3889); PORTB=0B00011010; delay_us(2667); PORTB=0; delay_us(388); goto loop; }