Attaching an LED to the Pi - Raspberry Pi Forums

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is possible attach led 3.3 gpio pin using 220 ohm resistor instead of 330 ohm resistor?

v=1.3
r=220 ohm
i=0.006 a

damage raspberry or led?

no. 220 ohm resistor , led forward voltage of 1.3 volt means led current 3.3-1.3 = 2.0v / 220 ohm = 9ma

max current per port pi can deliver 15ma, 9ma safe.

doubt forward voltage of led 1.3v, more around 2.0v, led current 3.3 - 2.0 = 1.3v / 220 = 0.005909090 or 6ma, safer.
seems more logical second scenario described.


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