Cytron Technical Forum

Hello,

i have problem to write programming code in MikroC Pro for PIC,since i'm quite new in micro c and programming,i do not know what my programming code mistake,btw i'm using PIC16F877A. Here i attach my code,hope someone can guide me,really appreciate it.

CODE: SELECT_ALL_CODE

int i,j,k;

void display_s1(int j,int i){
PORTB = 0b00100000 + j;
PORTB = 0b00010000 + i;

delay_ms(2);
}

void main() {
   TRISB = 0;
   PORTB = 0;

   while(1){
        for(k=0;k<100;k++){
        j = k%10;
        i = k/10;
        display_s1(j,i);
        delay_ms(200);
        }
   }
}


This is my another coding,also cant get nice count 00 to 99 because the 7-segments are alternating count.

CODE: SELECT_ALL_CODE

int i,j,k;

void display_s1(int j){
PORTB = 0b00100000 + j;
delay_ms(2);
}
void display_s2(int i){
PORTB = 0b00010000 + i;
delay_ms(2);
}

void main() {
   TRISB = 0;
   PORTB = 0;

   while(1){
        for(k=0;k<100;k++){
        j = k%10;
        i = k/10;
        display_s1(j);
        delay_ms(200);
        display_s2(i);
        delay_ms(200);
        }
   }
}


How your schematic?

Here my schematic,sorry for not include it earlier

I will use Timer Interrupt for the multiplexing and put transistor switching on common seven segment.

Hello,

Thanks for your feedback,timer interrupt..something new,i'll try,thanks again

I do not see a lookup table there. Depending on the connection of the 7-segment, your lookup table will be different. Therefore,

CODE: SELECT_ALL_CODE

const unsigned char sevenSegment[10] = { ... }

keeps all your patterns for each number per digit.

Then, to multiplex it, you

CODE: SELECT_ALL_CODE


while(1) {

1.) turn digit 1 on, and turn digit 2 off
2.) put digit (10s) into PORTB, like sevenSegment[x] where x is the number. If it's 1, then it'll show up one.
3.) delay for 1-5ms
4.) turn digit 1 off, and turn digit 2 on
5.) put digit (1s) into PORTB, like sevenSegment[x] where x is the number. If it's 1, then it'll show up one.
6.) delay for 1-5ms

}



There's also the timer and interrupt trick as Shahrul said. You can use that as well. This sample pseudocode is just for understanding only.

Yup, agreed with Shahrul where transistor is needed because the current required to be absorb is more than what single PIC pin can take.

what is the common polarity of the 7segment? Common anode or cathode? Is the 74 chip decoder?