Multiple conditions for if statement

Using Arduino Programming Questions
1

Hello,
I built a programmable thermostat for my radiators, it works well but i have a programmation problem: in one if statement I have multiple conditions but Arduino doesn't recognize one of it, in particulare my ifs are:

if((vett[num_hh] == 1 && temp < temp_set) || (onoff == 1)){ 
 close relay
}

else if ( (vett[num_hh] == 1 && temp > temp_set + 0.50) || (vett[num_hh] == 0)  || (onoff == 0) ){
open relay
}

the thing that happens is that when temp is greater than temp_set (and vett[num_hh] == 1) arduino opens the relay, why doesn't it consider the "+0.50" gap?

thanks to everybody who will answer...

2

Made a subtle change.

code snippets suck. What is the type declaration of temp and temp_set?

3

Nope. Adding redundant parenthesis does nothing. C++ operator precedence means those two statements are equivalent.

4

Add serial prints before the if statement printing out the state of the variables so you may see what's going on.

5

are two floats

6

I tried to remove the OR conditions (vett[num_hh] == 0, onoff == 0) leaving only

if (vett[num_hh] == 1 && temp >= temp_setf+0.50){
      
      open relay;
    }
    
    
    else if(vett[num_hh] == 1 && temp < temp_setf){
      close relay
    }

and it works, so there is a problem with syntax of OR (||) mixed with AND (&&) sub-condition, but i cannot understand what it is...

7

Ok, I figured out which was the condition which messed up things, this:

|| (onoff == 0)

This was in conflict with the others so the program didn't know what to do when onoff==0 and vett[num_hh] == 1 && temp < temp_setf, now it seems it works fine...

8

Yes, the program knew what to do. You had the logic wrong :slight_smile:

9

Hi,
Is temp_set, temp all float or int?
If int then 0.50 will possibly be read as 0.

Complete code would be nice.

Tom.. :grinning: :+1: :coffee: :australia:

10

all temp variables are floats

11

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