Want to set range for 2 different values on one digitalwrite pin

Projects Programming
1

So I just don't forget to mention that I'm absolute beginner working and learning code and arduino for less then a month for now, and mostly when I learn and search, I'm looking for working examples so I would understand what each line does and how.
So when I google around I find useful info, but I get stuck implementing it or using it in my sketch.
Maybe I'm missing some basics probably, but I'm trying to catch up.

So far this is what I came up with.

I want to control 1 fan on 1 relay and to set up min and max range for temperature and humidity

#include <Wire.h>
#include "DHT.h"
#include "LiquidCrystal.h"
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);
#define DHTPIN 8
#define DHTTYPE DHT22
DHT sensor(DHTPIN, DHTTYPE);

const int vent = 12;        // ventilation relay pin
const int humy = 11;        // humidifier relay pin

//values to turn off and on ventilation based on temperature and RH
float maxTemp = 28.50;
float minTemp = 26.80;
float maxHumy = 55.00;
float minHumy = 53.00;

//values to turn off and on humidifier based on RH
float maxHumy1 = 48.00;
float minHumy1 = 45.00;

void setup() {
  lcd.begin(16, 2);
  sensor.begin();
  digitalWrite(vent, HIGH);
  pinMode(vent, OUTPUT);
  digitalWrite(humy, HIGH);
  pinMode(humy, OUTPUT);
}

void loop() {
  lcd.clear();
  float t = sensor.readTemperature();    //reading the temperature from the sensor
  float h = sensor.readHumidity();       //reading the humidity from the sensor
  h = map(h, 21.8, 91.2, 15.6, 77.6);    //calibration I did to match my hygrometers
  // Checking if the sensor is sending values or not
  if (isnan(t) || isnan(h)) {
    lcd.print("Failed");
    return;
  }
  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(t);
  lcd.print("C");
  lcd.setCursor(0, 1);
  lcd.print("H:");
  lcd.print(h);
  lcd.print("%");

  //control for ventilation 
  if (t >= maxTemp) {
    digitalWrite(vent, LOW);
    lcd.setCursor(9, 0);
    lcd.print("V:On");
  }
  else if (t <= minTemp) {
    digitalWrite(vent, HIGH);
    lcd.setCursor(9, 0);
    lcd.print("V:Off");
  }

  //controll for humidifier 
  if (h <= minHumy1) {
    digitalWrite(humy, LOW);
    lcd.setCursor(9, 1);
    lcd.print("H:On");
  }
  else if (h >= maxHumy1) {
    digitalWrite(humy, HIGH);
    lcd.setCursor(9, 1);
    lcd.print("H:Off");
  }
}
double map(double x, double in_min, double in_max, double out_min, double out_max) {
  return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}

I tried it like this, but then it only triggers at max values(maxTemp and maxHumy)

  //control for ventilation 
  if (t >= maxTemp || h >=maxHumy) {
    digitalWrite(vent, LOW);
    lcd.setCursor(9, 0);
    lcd.print("V:On");
  }
  else if (t <= minTemp || h <=minHumy) {
    digitalWrite(vent, HIGH);
    lcd.setCursor(9, 0);
    lcd.print("V:Off");
  }

Also I have trouble displaying correctly digitalwrite when it is in the range, it actualy doesnt display at all, but above max or under min its all ok.
That you would say I need boolean there and when I searched bool I got confused even more, as how do you add or set 1 pin for one bool, and 2nd pin for other bool ?

EDIT: This post was changed due to bad/wrong expresion.

2

Help ?

3

Add some debugging prints so you can see what values h and t have as well as some that tell you where execution went.

4

Well everything works fine, I'm just not sure if I wrote these lines correctly for desired operation

//controls ventilation
  if (t >= maxTemp || h >= maxHumy) {
    digitalWrite(vent, LOW);
    lcd.setCursor(9, 0);
    lcd.print("V:On");
  }
  else if (t <= minTemp || h <= minHumy) {
    digitalWrite(vent, HIGH);
    lcd.setCursor(9, 0);
    lcd.print("V:Off");
  }
5

I modified 1st message since opening this topic, as I probably wasn't clear what I want to do and how, sorry if I'm being too much noobish for you, but I'm still learning

6

If the code works the way you want it to work, then you coded it correctly.

Paul

7

Well, it works, but not the exact way I want it. . .