I actually read the complete 8052 tutorials section and have allready build some example projects.

I allready made a little counter which counts up at 1 count per second and outputs that to a port.

Thats where I saw that the LED (to display the output) is connected between the PIN and VCC.


With the electrical knowledge I have I always assumed that the output of a pin would have to be connected to the led and the other leg of the led to GND, but it seems to be the opposite for 8051.



When my counter runs, I actually see that an active 1 on the port makes my LED not light up and a 0 lights up, so I must have had a weak moment some hours ago to state that you have to pull them down.

As I believe now the port is at 0 unless you pull it to +5V by writing a 1 to that port pin. Am I right now ?