LED low brightnes on DO 8-12

Hey all,

Except from reading the forum this is now my first post, nice!

Problem is, I've got 12 LED's now connected to DO 2-13 of my Duemilanove. The LED's on 2-7 and 13 are nice and bright, but those on pins 8-12 shine very dim. It's not the LEDs themselves because they do shine bright on the other DO's.

I've got 100 Ohm resistors for each led resulting in 19mA per led, and I'm powering only 3 at the same time. The board is powered from the the USB.

Is there a power limitation on the 8-12 pins such that I may need switching transistors anyway? I tested the LED's before but only on pins 0-6, so I figured it worked fine without transistors...

(writing this the question pops into mind if maybe I need a secondary power source for DO 8-12 if the board is powered from USB?)

Hope to get some advice!

Han

Is there a power limitation on the 8-12 pins

Nothing that isn't on the other pins.

Are you sure you are setting these pins as outputs in your sketch, that is normally the problem with this sort of issue.

Nothing that isn't on the other pins.

Unless some damage has already been done...

Grumpy_Mike:
Nothing that isn't on the other pins.

Are you sure you are setting these pins as outputs in your sketch, that is normally the problem with this sort of issue.

Hey Mike, you're right. I used the test program I wrote but expanding from 6 to 12 LEDs I didn't declare the pins as outputs...

Thanks!