ard. uno output pins problem, 5 to 9, 10 is ok.

leds with 100 ohm resistor, working with the 3-light project from adafruit, the led on pin 10 works ok, full brilliance.
the leds on pins 8 and 9 half-light. i found no ac component on pin 10, but around a half-volt on 8 and 9 when "lit".
the program compiles and works ok except for the partial brilliance.
pin 10 is at 4.5+ vdc. at the arduino side of the resistor..(correct.)
pins 8 and 9 only go to 1.55 vdc at their resistors.
i swapped the pin numbers in the arduino to 6 and 7 and reloaded, same symptom.
and, of course, i swapped the led, to see that they are all ok on the pin 10 location.
i must be missing some setup on those pins, or what?
sam

can we see your code?

Are you setting the pins to OUTPUT?

yes, the code works and is correct.
i'm new at this forum and not yet familiar with including the attachment. i thiink i know. now, looking at the bottom of the page.
i will recheck the code, it is from the suggested code in the adafruit project. it also verifies and loads ok.
i'm on a different PC now.
more later, thanks, sam

Zammy, maybe totally simplify this to try to find what's really happening...

GO back to Blink example. Onboard LED blinks OK??

Then change only that 13 to some other pins. Also try #14 to 19 (The "analog" pins which can also be outputs)..

I've tested quite a few Arduinos with my Test Shield, and have not seen any one pin more that a small amount different...

Let us know...

smeezekitty:
(SIG) Solid state rectifiers are the only REAL rectifiers.

Hey, Smeezekitty, you gotta problem with 8008's?? Bet you never even been Blue in the face... :slight_smile:

Yes, Actually.
For various reasons.
Such as wasted power, generated heat and reliability problems.

Filament Vf 5 Volts / If: 6.75 Ampere

Yeah....

Hi Smeezekitty, Not to take this TOO far OT (How could we BE farther??) , What is the background to your unusual Sig??

Agree with ALL your reasons; About 1964 I built a string of RCA Silicon Diodes with parallel R and C to replace a pair of 8008's in an RCA 1Kw broadcast transmitter. After too many cold-morning trips to fix circuit-breaker dropout on 8008 arc-back.

... now we return you to you previously scheduled program...

What is the background to your unusual Sig??

What part of it?

thanks, terry king. good thought to try to use the local led.
will try it asap.
sam

found the PROGRAM problem! mea culpa.
i had a comma and space between pinMode and (yellowPin, HIGH)
these things are just a bit sensitive to syntax, eh?
(blush!, started working in computers in 1959 at philco) :blush:
thanks, all.
sam