Cool! Maybe if I start with some real basics, I'll be able to follow along and others will benefit from my noob-level questioning!
Perhaps the most simple: control ON/OFF of a 12V relay. I understand I cannot drive the relay coil magnet directly, but this guy seems to do it. Is there support circuitry on the UNO that's being used, or how does he do it?
https://www.google.com/search?q=cont...TF-8#kpvalbx=1
Once I know how to do ON/OFF, I'll ask about power transistors. But let's start with ON/OFF!
int in1 = 7;
void setup() {
pinMode(in1, OUTPUT);
digitalWrite(in1, HIGH);
}
void loop() {
digitalWrite(in1, LOW);
delay(3000);
digitalWrite(in1, HIGH);
delay(3000);
}