mytutorialcafe.com

[cak kalim]

Ive just try the tutorial on http://mytutorialcafe.com/Microcontroller%20Application%20Motor%20Stepper.htm
I try to drive the motor using P0, but never work.
When I attach led tester on P0 it works fine (the led rotate like the source code)

Then I try to change it to P1 and works fine.

Anyone know why?

[myturf]

In my opinion these port doesn't have pull up resistor, you may use this port if you put resistor up ( 10k) to Vcc, and don't forget to add diode betwen emitor and Vcc.

I hope this answer can help you.

[cak kalim]

Thanks for the tips. Yesterday I tried it and works. Now I add pull up resistor for other ports.