Apologies for the number of probably very basic questions I've asked over the past few days. But I could use a little more help.
There's an existing circuit I'm trying to hack in to, but before attempting it, I wanted to get the basic idea of something down first.
Let's say I have a circuit, in this example it's a simple LED. It's powered from a 5v source that also powers my Arduino through a USB connector.
What I want to do, is have the Arduino ground that circuit and cut off the power to the LED. I'm only using the LED circuit as an example since if it works with those current hungry buggers then it should work with anything right?
Initially, I tried using a digital output pin driven LOW and connected (first through a resistor, later not) to the LED's anode. That didn't work - it did in Virtual Breadboard but not in real life. Damn.
Then I tried a basic transistor circuit and must have gotten something wrong because when the Arduino pin (HIGH) switched on the transistor, the LED circuit stayed quite happy but the transistor got very hot and then burnt my finger (leaving a nice blister) when I removed it from the breadboard.
Is a relay my only real option here?
Hoping someone can point me in a better direction. Please - before I damage another bass-playing finger? :