Sensor help with 4 parameter thresholds. Please7

Other Hardware Sensors
1

I cant seem to code this correctly. Its a basic gardening monitor circuit that alerts me if any of the 4 if statements are true. But the 4 if statments seem to cancel eachother out. As long as one of the if statments are true. My sketch wont do anything. Its supposed to stay green unless one or more f the if statements goes outside my thresholds. But it will only stay green nonmatter what. Please help

#include "DHT.h"
#define DHTPIN 2 
#define DHTTYPE DHT11

int greenled = 3;
int redled = 4;

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(9600);
  Serial.println("DHT Sensor Reading");

  pinMode(greenled, OUTPUT);
  pinMode(redled, OUTPUT);

  dht.begin();
}

void loop() {
  delay(2000);

  float h = dht.readHumidity();
  float t = dht.readTemperature(true);

  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.print("Temperature: ");
  Serial.println(t);

  if(t > 80){
    digitalWrite(greenled, LOW);
    digitalWrite(redled, HIGH);
  } else {
    digitalWrite(redled, LOW);
    digitalWrite(greenled, HIGH);
  }

    if(t < 65){
    digitalWrite(greenled, LOW);
    digitalWrite(redled, HIGH);
  } else {
    digitalWrite(redled, LOW);
    digitalWrite(greenled, HIGH);
  }

    if(h > 40){
    digitalWrite(greenled, LOW);
    digitalWrite(redled, HIGH);
  } else {
    digitalWrite(redled, LOW);
    digitalWrite(greenled, HIGH);
  }

    if(h < 30){
    digitalWrite(greenled, LOW);
    digitalWrite(redled, HIGH);
  } else {
    digitalWrite(redled, LOW);
    digitalWrite(greenled, HIGH);
  }
}
2

Hi, you didn't get an answer for your Blynk question. Sorry. I think not many people use Blynk. I tried Blynk, but it would not run on my tablet.

Can you tell in words, for each of the conditions when the led should turn red ?
The temperature of 80 or 60 degrees Celsius is very high, isn't it ?

There is a programming thinking error in the sketch. If the humidity is above 40, you still turn on the green led because it is not below 30. You can combine those if-statements or use a default setting.

Combine them:

if( h > 40.0 || h < 30.0)          // outside the limits ?
{
  digitalWrite( greenled, LOW);
  digitalWrite( redled, HIGH);
} 
else 
{
  digitalWrite( redled, LOW);
  digitalWrite( greenled, HIGH);
}

Use a default:

boolean alarm = false;     // set default : all normal, no alarm

if( h > 40.0 )
{
  alarm = true;
}

if( h < 30.0)
{
  alarm = true;
}

if( alarm)
{
  digitalWrite( greenled, LOW);
  digitalWrite( redled, HIGH);
} 
else 
{
  digitalWrite( redled, LOW);
  digitalWrite( greenled, HIGH);
}

If you understand this, you have to add the temperature. Give it a try and show us your sketch.