I just saw a new Instructable. Great to see people posting new projects.
a transistor to drive a led?
You could ask him about that in the Instructable comments? I don’t know the reasons for that. I just like seeing people get the “Imp bug”. I especially like to see young people getting into electronics (ages 10-20). Put away the video games and actually build something with your hands.
From the article:
Next we need to make sure the Imp can control our LEDs that light the button. I'm using the common cathode diffused RGB LED from Sparkfun, which needs to pull 20 mAs for each color. Unfortunately while going through the Electric Imp documentation, I found the Imp's GPIOs can only source/sink up to 4 mAs, which means we can't power the LEDs directly from the Imp. To address this, a common strategy is to use transistors to turn on the LEDs.
What would be a better way to do this? Just curious, I need to integrate LEDs in my current project and was going to go this route.
NPN transistor is a good and typical way; robust and easy. You can also use a FET
related discussion here: