Aamir, you told us, that you have a BDX54C and want it to make a LED shine. I drew a schematic for you and told you that the only way to make the LED shine with this transistor is to apply low level to the base of Darlington. I also told you that driving high current LEDs in this way is a good idea, because of the power-on reset, when the standard 8052 and other micros emit high state. Turning-on the LEDs by high state from micro, on the other hand, would barbecue your LED matrix. So, be happy that the BDX54C turns-on by receiving low state.

If you see the LED shine when applying low state and high state, then you must have done something wrong!



Cut the connection between 2k2 resistor and micro. Connect this side of 2k2 resistor to ground and the LED must shine bright. Connect this side of 2k2 resistor to Vcc and the LED must turn-off. Between these two conditions there must be a sharp difference. Do you see it? Eventualy, you have confused the terminals of BDX54C? Or you destroyed the transistor when experimenting?

Kai