thanks guys for all your replies.
Hi hyeneddy,
ooh..i forgot to mention that I've used other I/O pins for other purposes. 8 for matrix keypad, 4 for leds, and buzzer...most of this applications works well...except for the 10 digits display which turns out to be very dim.
To clarify everything, I wish to use one 4017 to replace 10 transistors to select each digit at a time. That is what I am trying to do. at the 10 output pins of 4017, only one will turn on each time, it is like when digit 1 is on, others are off, when digit 2 is on, all others are off and so on. The 4017 is activated by a clock pulse, which is taken care by PIC software. Does this clarify everything?
BTW hyedenny, how do you run simulation on PIC? I mean where do you find a software that can simulation your circuit using PIC?
hi ljcox,
is it ok to remove base resistor? I thought R2 is to limit the current and prevent PIC from damaged?
I've tried to placed R1 on emitter side and connect collector to Vcc. the segment are then connected to emitter on simulation and practical, the result is still very dim.