How to make IF statement for if something changes in Arduino

[Clanscorpia]

Hello,

I'm trying to make an Arduino program where a serial message is displayed and when something comes in but I dont know what I would do for the If statment to show what happens if the value of a button changes. if ( I dont know what to put here )

{

}

What do I put? Just the variable and then =! ?

[Philcat101]

put an if statement in a loop always checking the current condition compared to the previous one

[DrM]

somthing like this (sorry if the code isnt optimal)

_______________________________________

 

bool buttonold = digitalRead();

bool buttonnew = digitalRead();

 

void loop(){

buttonnew = digitalRead();

if(buttonnew != buttonold){

   Serial.println(message);

   buttonold = digitalRead();

}

}

[Philcat101]

Just now, DrM said:

somthing like this (sorry if the code isnt optimal)

_______________________________________

 

bool buttonold = digitalRead();

bool buttonnew = digitalRead();

 

void loop(){

buttonnew = digitalRead();

if(buttonnew != buttonold){

   Serial.println(message);

   buttonold = digitalRead();

}

}

 

2 minutes ago, Philcat101 said:

put an if statement in a loop always checking the current condition compared to the previous one

Exactly what I was saying, good idea. OP read this

[Clanscorpia]

1 minute ago, DrM said:

somthing like this (sorry if the code isnt optimal)

_______________________________________

 

bool buttonold = digitalRead();

bool buttonnew = digitalRead();

 

void loop(){

buttonnew = digitalRead();

if(buttonnew != buttonold){

   Serial.println(message);

   buttonold = digitalRead();

}

}

Damn, I didn't want to write that kind of statement, they take ages

[Clanscorpia]

9 minutes ago, DrM said:

somthing like this (sorry if the code isnt optimal)

_______________________________________

 

bool buttonold = digitalRead();

bool buttonnew = digitalRead();

 

void loop(){

buttonnew = digitalRead();

if(buttonnew != buttonold){

   Serial.println(message);

   buttonold = digitalRead();

}

}

Wait I see what you did there. Last time I did something like that is was much different. Thank you very much. It's going to be used for a littleBits  project to test wireless latency and if you want I can link you to the final outcome

[DevBlox]

Constant polling of a pin is not optimal, you need to use ISR on a pin that executes a function of yours, that's the best way to implement such a thing.  Refer here.