Help please!

Using Arduino Programming Questions
#1

Hi

I’m fairly new to arduino and I’m struggling with my sketch. I can’t seem to get it to work properly.

It seems like it’s something with the if’s. I can’t get the arguments to work. the lcd prints the prsV, no load, heating up and the temperature. When pressure is applied the temperature rises and the lcd prints no heat .

Please help me to see if i’ve gotten something wrong…

#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x3F,16,2);  // set the LCD address to 0x3f for a 16 chars and 2 line display

const int temperaturePin1 = A1;    //temp sensor heater
const int temperaturePin2 = A2;    // temp sensor animal 
const int prs_Pin = A0;           // pressure sensor

const float VCC = 4.65; // Measured voltage of Ardunio 5V line
const float R_DIV = 4700; // Measured resistance of 4,7k resistor

int relayPin1 = 8;  // Pin of Relay Module start heater
int relayPin2 = 7;  // Pin of Relay Module  coling fan
int relayPin3 = 6;  // Pin of Relay Module sensor heater
int relayPin4 = 5;  // Pin of Relay Module circulation


void setup()
{
 pinMode(relayPin1, OUTPUT);
 pinMode(relayPin2, OUTPUT);
 pinMode(relayPin3, OUTPUT);
 pinMode(relayPin4, OUTPUT);  // Set Pin connected to Relays as an OUTPUT
 pinMode(prs_Pin, INPUT);     //  Set Pin connected to relays as an input
 
 digitalWrite(relayPin1,0);
 digitalWrite(relayPin2,0);
 digitalWrite(relayPin3,0); 
 digitalWrite(relayPin4,0);   // Set Pin to 0 to turn Relays OFF

lcd.init();                      // initialize the lcd 

lcd.backlight();


}


void loop()
{
 
 
 int prsADC = analogRead(prs_Pin); // If the prs has no pressure, the resistance will be near infinite. So the voltage should be near 0.
 float prsV = prsADC * VCC / 1023.0;   //stämmer
 
 float voltage, degreesC1, voltage2, degreesC2;

voltage = getVoltage(temperaturePin1);
degreesC1 = ( (voltage * 100)-4 );
 voltage2 = getVoltage(temperaturePin2);
degreesC2 = ((voltage2 * 100));

if (prsV < 0,03){      // If the analog reading is near zero
   lcd.setCursor (5,0);
   //lcd.print(prsV);
   lcd.print("no load");
   
 if (degreesC1 < 30){
 digitalWrite(relayPin1, 1);
 lcd.setCursor (0,1);
 lcd.print("heating up ");
 lcd.print(degreesC1);
 lcd.setCursor (0,0);
 lcd.print(prsV);
 }
 else 
 {  
 digitalWrite(relayPin1, 0);
   lcd.clear();
   lcd.setCursor (0,1);
 lcd.print("no heat");
   lcd.setCursor (11,1);
   lcd.print(degreesC1);
   lcd.print(prsV);
 }
}  

  
  
else
{
 lcd.clear();
 lcd.setCursor (5,0);
 lcd.print("load on");
 //delay(1000);
    
    if(degreesC2 < 38){
        digitalWrite(relayPin1, 1);
        lcd.setCursor (0,0);
        lcd.print("heating ");
        lcd.print(degreesC2);
     }
     else if(degreesC2 < 40){
       //digitalWrite(relayPin1, 0);
      // digitalWrite(relayPin2,1);
       lcd.setCursor (1,0);
       lcd.print("circulation");
     }
     else 
     {
       digitalWrite(relayPin1, 0);
       digitalWrite(relayPin2, 0);
       digitalWrite(relayPin3, 1);
       lcd.setCursor (1,1);
       lcd.print("cooling");
      }
}

  
 

 
delay (1000);
}


float getVoltage(int pin)
{
return (analogRead(pin) * 0.004882814);
}

Thanks!

#2

Please modify your post and use the code button </> so your code looks like this and is easy to copy to a text editor. See How to use the Forum Your code is too long for me to study quickly without copying to a text editor.

…R

#3 
  if (prsV < 0, 03)      // If the analog reading is near zero

Not how you test if a value is in a range

 if (prsV >= 0 && psrV <= 3) //if the reading is between 0 and 3
#4

One thing that caught my eye

if (prsV < 0,03)

Change the comma to a dot.

#5 
  pinMode(prs_Pin, INPUT);     //  Set Pin connected to relays as an input

prs_Pin has a relay attached?

const int prs_Pin = A0;           // pressure sensor

That makes that comment look pretty stupid, then.

Since you are using prs_Pin as an analog pin, you almost certainly do not want to be diddling with the digital nature of that pin, which is what pinMode() does.

#6

Thanks you all, Its now working!!!!

#7

Most of the topics on this forum are requests for help, so a subject of "Help please!" is not useful. Polite, perhaps, but not useful.

#8