Hey all, I am trying to light a string of LEDs in a row using a transistor and my Diecimila. I have 6 LEDs using 2 forward volts a 1ohm resistor and a NPN 2n4401 transistor. I have the LEDs hooked up to an external DC power supply and the Diecimila hooked up to my laptop's USB. Does the Diecimila h…

Transistor question

westfw October 14, 2008, 5:02am 2

The arduino needs to share "Ground" with your transistor/supply, like in the following picture:

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