I've recently started doing basic diode connections (red and green diodes). I've also got blue diodes, but there's one thing that prevented me from connecting them already, namely - the specs say they're 3.3V.
While calculating resistor value, I'm doing simple:
3.3V - ULed / 2mA to obtain resistor value needed to draw default 2mA.
But if the forward voltage of blue diode is said to be same as supply voltage of my GPIO pins, how would then things work? Will the rpi be just 'unable' to power up the led? And if it will (and diode will do just fine with lower voltage), how should I calculate resistor value?