Arduino : can I loop in loop()? - arduino

Question

I'm wondering if there are any reasons not to loop inside the loop() function.
To illustrate my question, let's say I want to make a LED blink a thousand times.
Here are two ways to do it with the Arduino.
In the following one, I make sure not to "lock" the loop() function :
const int PIN_LED = 2;
const int BLINKING_LIMIT = 1000;
int blinkCount = 0;
void setup() {
// initialize serial:
pinMode(PIN_LED, OUTPUT);
}
// Here, I make sure not to "lock" the loop() function
void loop() {
blinkCount++;
if (blinkCount < BLINKING_LIMIT) {
digitalWrite(PIN_LED, HIGH);
delay(200);
digitalWrite(PIN_LED, LOW);
delay(200);
}
}
In the second one, there is a long loop (which could last even longer) in the loop() function. The Arduino is "locked" inside the for loop :
// Here, I make sure not to "lock" the loop() function
void loop() {
for (int i = 0; i < BLINKING_LIMIT; i++) {
digitalWrite(PIN_LED, HIGH);
delay(200);
digitalWrite(PIN_LED, LOW);
delay(200);
}
}
What is the best practice ? Should I care not to "lock" the loop() function, or can I just don't care ? Would an infinite loop inside the loop() function be acceptable ?

Answer 1

loop() and setup() are just 2 functions defined for Arduino. It will be compiled with the main code for your board.
The code of the Arduino board will be something like:
void main()
{
setup();
for(;;) {
loop();
}
}
And you just have the possibility to write the code for setup and loop.
It is like #Piglet said. It is your code and you can write it how you want.
You can not "lock" the loop, since it is not an interrupt and there is no OperatingSystem behind your loop.
Once the loop is terminated, it is called automatically again. So you can also write:
void loop()
{
for(;;) {
// your code
}
}
If you like it, so the loop will never terminate and you can write it like on a 8051 processor ;)

Answer 2

Just don't care. Nesting loops is super common practice in programming. Many problems cannot be solved efficiently without it.
It is your program. You may stay within a loop as long as you wish. Your Arduino won't timeout or anything.

Answer 3

Personally, I would use the second code. It's precise and short. Who wants to make the code long and boring. Loop will stop when you want to stop just add a condition, so don't care until and unless your code works perfectly.

Answer 4

If you just want to make a LED blink, it's not important but if you want to add something to your code, the behavior will be different:
void loop() {
blinkCount++;
if (blinkCount < BLINKING_LIMIT) {
digitalWrite(PIN_LED, HIGH);
delay(200);
digitalWrite(PIN_LED, LOW);
delay(200);
}
//ANYTHING ELSE
}
In this part, your LED will blink and the rest of your code will be executed in each 400ms about.
void loop() {
for (int i = 0; i < BLINKING_LIMIT; i++) {
digitalWrite(PIN_LED, HIGH);
delay(200);
digitalWrite(PIN_LED, LOW);
delay(200);
}
//ANYTHING ELSE
}
In this part, your LED will blink "BLINKING_LIMIT" times and only after, the rest of your code will be executed.
Just be careful if you want to add something.