And in fact, the particular way that Arduino repeatedly calls the loop() function makes knowing a bit about scoping nearly mandatory: all of your function-call-duration variables get wiped each ...

Long story short: functions need prior declaration in C, and your “.ino” code defines setup() and loop() but never declares them. So that’s one thing that the Arduino IDE does for you.

The Arduino ... the map() function, as you can see in this Analog In, Out Serial sample sketch. The second way to periodically change your analogWrite() value is with the for loop.

The TX LED has a defined Arduino pin // the setup function runs once when you press reset or power the board digitalWrite(RXLED, LOW); // set the LED on digitalWrite(TXLED, LOW); // set the LED on The ...