Buying resistors for Arduino

[saildude]

I did the calcs from the data sheet and missed something - so thus the bracket the values, and at the cost for a 100 roll was not too bad, maybe measuring the voltage drop and supply voltage would have been another way, was last year so don't remember all what I tried - also using a chip that sank the current so did not have 5 v available

Also seems to me the LED's had a curve for the current and the limited data sheet I had did not show the curve, just the nominal voltage drop

But I will give your suggestion a try on the next project

thanks

[wvmarle]

As with all diodes forward voltage will go up a bit with increasing current - they're not ideal components.