7Digit Display counting bug - c

Question

I am trying to fix the bug in my code - I have 7Digit display, which must count up from 0 to 99 when button is not pressed, or count down from 99 to 0 when button is pressed.
I have the issue with counting up, the issue happens, when the display must show numbers as 10,20,30 etc. While countin it up, after number 09 there is 00 instead of 10, after 19 there is 10 instead of 20 etc.
I am attching below a fragment of code responsible for counting up and down:
void Refresh_Display() {
AT91C_BASE_PIOB->PIO_CODR = A|B|C|D|E|F|G;
}
void set_Number(int number) {
AT91C_BASE_PIOB->PIO_SODR = LEFTDIGIT;
AT91C_BASE_PIOB->PIO_CODR = RIGHTDIGIT;
Refresh_Display();
Display_Number(number%10);
delay(5000);
AT91C_BASE_PIOB->PIO_SODR = RIGHTDIGIT;
AT91C_BASE_PIOB->PIO_CODR = LEFTDIGIT;
Refresh_Display();
Display_Number(number/10);
delay(5000);
}
void countdown(int i) {
while(1) {
if(i<=0) {
i = 99;
}
set_Number(i);
i--;
if(!BP1_Status) {
counter = i;
break;
}
}
}
void countup(int i) {
while(1) {
i++;
if(i>=99) {
i = 0;
}
set_Number(i);
if(BP1_Status) {
counter = i;
break;
}
}
}
int main(void){
Port_init();
Button_init();
while(1) {
for (volatile int i=0;i<100;i++) {
if(BP1_Status) {
countdown(counter);
} else if (!BP1_Status) {
countup(counter);
}
}
}
}

Answer 1

I have a solution for that problem:
In the ARM processor AT91SAM9263 there are registers PIO_CODR and PIO_SODR. The first one register is refreshing data, the second one Sets the data to be driven on the I/O line.
I have swapped the method of display the numbers on two 7Segment Displays. On the left, there are displayed, the decimal numbers are displayed as number/10 and the units as numbers%10to receive 0 digit on second display while showing 10 or 20 value.
void set_Number(int number) {
AT91C_BASE_PIOB->PIO_CODR = LEFTDIGIT;
AT91C_BASE_PIOB->PIO_SODR = RIGHTDIGIT;
Refresh_Display();
Display_Number(number/10);
delay(5000);
AT91C_BASE_PIOB->PIO_CODR = RIGHTDIGIT;
AT91C_BASE_PIOB->PIO_SODR = LEFTDIGIT;
Refresh_Display();
Display_Number(number%10);
delay(5000);
}