easy question- but i forgot

[jimbob]

Which side of a led 5mm is negative..the long end or short end? I cant remember..i think the short but not sure..

thanks

[Sic]

yup, the short end... and the side with the flat part...

you could test by putting a resistor on what side you think is negative and connect it to a current higher than 1.5 volts.

i believe red needs 1.5 volts or more...