Arduino Fundamentals: Part I: Quiz

Hmmm, not so sure about question 13 as you can create code such that either can apply "Place code in _____ to make an LED flash 10 times."

Hmmm, not so sure about question 13 as you can create code such that either can apply "Place code in _____ to make an LED flash 10 times."

There's the right answer, the wrong answer, and the best practice answer.

Not sure about a "best practice" in this case.

Case 1.

void setup() {

for (int i = 0; i < 10); i++) {insert LED code}

}

Case 2.

void loop() {

  static int i = 0;

  if (i < 10) {

    insert LED code

    i++;

  }

}

I believe it's considered that the setup would only be for one-time run commands and functions, so typically you wouldn't want to run code in a loop within it, as it's delaying the setup. Similarly not having a loop but having ten lines of 'blink' would not be very optimal.

Instead you'd set it up, and then have the loop that's running to execute the ten times to blink, as it's looping anyway. A trade off might be made in a condition statement, though it then depends on your code, however because it's Arduino it's going to be executing a loop anyway and so it would be somewhat redundant if you put the code you intended to execute in the setup function.

Personally I may not have declared i within the scope of the loop, I may have considered declaring it as a more global variable and re-used it as necessary.

So the 'best answer' may be, use the loop that's already there, rather than introducing an additional one. Similar principle to games programming.

Placing the flashing code in setup() requires a loop (or a repetition of code).

Contrasting to that, placing the code in loop() requires some code to stop the flashing once 10 cycles have passed.

So flashing in setup() might be somewhat easier 

du00000001 Duh this is the way it should have been done NEVER put executable code in setup!! setup() is akin to c.h file

what I show below  is that I used a variable 'setflash' and I set it to 0

then in loop() I test 'setflash' to make sure it's still 0

if its still 0 then I call my function flash() and then bump setflash to 1

In this way, no-mater how many time loop() runs for flash will only be called the first time around! and never again.

void setup() {

int setflash = 0;}

void loop {

if (setflash == 0) {

       flash();

       setflash =1; }

else { other stuff }}

void flash( )

// the code

}

Christina, I think that’s a personal style. Not a common one. (edit: and loop() would have no access to setflash because it’s in local scope of setup(). )

Most people put variables outside the setup and loop, initialise them, and set up initial state in setup,

And then the lifecycle code in the loop.

Christina, as Jan already commented: your code won't work because setflash would be local to setup().

setup()   basically equals the initialization that's (maybe called as an initialization block) at the beginning of the "normal" main().

loop()     equates the FOREVER loop in a standard main().

I resently gauged a pit specific to the Arduino sketches, erroneously putting some variable declarations/initializations into the loop() function:

while this is considered reasonable style in standard C programming (putting these into main() ), in sketches the initialization is repeated every time loop() is executed. Not exactly what I wanted to have 

So be advised: loop() is not main() - it's only the endless loop in main().