Seeking quick advice

Projects Programming
1

I am sending the temp to float f,

i would like to compare that value to a benchmark temperature to turn on or off a relay.

should i be defining a int value before the void setup

example:

Int benchmarktemp = 68;

Voidsetup()
ect….

How should i convert that 68 so it knows I'm talking about a temperature value and not a char value

3

if temp is a float then you will need benchmarktemp to be a float to otherwise you are comparing apples and oranges.

float benchmarktemp = 68.0;
4

Strattonstudios:
I am sending the temp to float f,

i would like to compare that value to a benchmark temperature to turn on or off a relay.

if (f > benchmarktemp)
  turnOnRelay ();
5

Ive posted the code i have as of now. Even setting the the benchmark as a float seems to have no effect on the relay. The relay remains switched constantly.

Thanks guys i appreciate the responses.

Greg

fancontrol.ino (1.06 KB)

6

This code can never be executed:

  if (f >= benchmarktemp);
    digitalWrite(RELAY1,LOW);

Move it out of the block that is run if you detect nan. i.e. below the closing brace that currently succeeds it.

7

Moved still no response

fancontrol.ino (1.06 KB)

8

The semicolon on this line means that the digitalWrite after it will always be run, regardless of the temperature - get rid of it.

  if (f >= benchmarktemp);

But since there's nothing in your code to set that pin HIGH, once it's LOW, it'll stay that way, just as it does now.

9

You didn't fix this yet:

if (f >= benchmarktemp);
digitalWrite(RELAY1,LOW);

to:

if (f >= benchmarktemp) {
digitalWrite(RELAY1,LOW);
}

What will make it go high? You need code for that.

10

AHHHH got it guys thanks a bunch!!!!!