LED with Transistor

Hi guys... I am wondering how do we light up so many LEDs in one I/O pin. I have around 50 LEDs that need to be turned up which are controlled by PIC16F84A. So, I am thinking of putting a BC547C transistor as the switch. However, I am not sure about the connection and also the code. Does anybody can give me any suggestion?

I've attached my schematic. Thank you

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Originally Posted by mimi_deviL

Hi guys... I am wondering how do we light up so many LEDs in one I/O pin. I have around 50 LEDs that need to be turned up which are controlled by PIC16F84A. So, I am thinking of putting a BC547C transistor as the switch. However, I am not sure about the connection and also the code. Does anybody can give me any suggestion?
I've attached my schematic. Thank you

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~1K resistor on the base...
Might want to put a series resistor inline with the LEDs, just as a precaution against shorts.
Better put a decent cap on the PIC's Vdd/Vss. $20 says when the PIC turns on all of those LEDs, it'll clobber the power supply for a split second and reset your PIC.

thanks a lot yeah! Now I got it