I’m multiplexing 5 common cathode small red seven segments. Segment patterns come from PORTB (without resistors) & common cathodes driven by PORTA without using any transistors.
The problem is display brightness is very low & each digit segments are different brightness.
The problem is display brightness is very low & each digit segments are different brightness.
Code:
movf Digit1,W ;get the D1 segment pattern
movwf PORTB
movlw b'11110' ;make RA0 low
movwf PORTA
call Del_770uS
movf Digit2,W ;get the D2 segment pattern
movwf PORTB
movlw b'11101' ;make RA1 low
movwf PORTA
call Del_770uS
movf Digit3,W ;get the D3 segment pattern
movwf PORTB
movlw b'11011' ;make RA2 low
movwf PORTA
call Del_770uS
movf Digit4,W ;get the D4 segment pattern
movwf PORTB
movlw b'10111' ;make RA3 low
movwf PORTA
call Del_770uS
movf Digit5,W ;get the D5 segment pattern
movwf PORTB
movlw b'01111' ;make RA4 low
movwf PORTA
call Del_770uS
return