USB LED Tester and Breakout

If you’re anything like me, you’ve probably got various LEDs knocking around left over from previous projects or salvaged from equipment. Some of them you might have had for years, and others might be clear ones and you’ve long since lost track of what colour they are, what is their forward voltage, and whether they even still work. True, it’s easy to knock up an improvised LED tester with a battery and a resistor, and preferably a breadboard or a few clip leads, but first you’ve got to find those bits. Much nicer, then, to have a ready made tester which cost you next to nothing to build and can take power from a computer’s USB port, a USB charger or a USB power bank.”