Why is my lcd display not showing any values?

Question

#include <Wire.h>
#include "DFRobot_LCD.h"

DFRobot_LCD lcd(16, 2); //16 characters and 2 lines of show

#define PH_PIN 25 
float voltage,phvalue,temperature = 25;

float acidVoltage =  (1990); //buffer solution at 4.o 
float neutralVoltage = (1389);   //buffer solution at 7.o 

void breath(unsigned char color){
     for(int i=0; i<255; i++){
        lcd.setPWM(color, i);
        delay(5);
    }

    delay(500);
    for(int i=254; i>=0; i--){
        lcd.setPWM(color, i);
        delay(1000);
    }

    delay (300) ;
}

void setup()
{
    Serial.begin(11520);
    // LCD Begin //
   lcd.init();
   lcd.setCursor(4,0);
   lcd.print("Welcome");
   delay(3000);
   lcd.clear();

   lcd.setCursor(3,0);
   lcd.print("Reading PH");
    delay(5000);
   lcd.clear();

  lcd.setCursor(3,0);
   lcd.print("Please Wait");
   delay(5000);
   lcd.clear();
}

void loop(){
  void loop1();
  void loop2();
  void loop3();
}

**void loop1(){
  static unsigned long timepoint = millis();
  if(millis()-timepoint>1000U){
    
    timepoint = millis();
    // timepoint = read temperature 

    voltage = analogRead (PH_PIN)/4095.0*3300; 

    float slope = (7.0-4.0)/((neutralVoltage-1500)/30 - (acidVoltage-1500)/3.0);
    float intercept = 7.0 - slope*(neutralVoltage-1500)/3.0;

    phvalue = slope*(voltage-1500)/3.0 + intercept;   // y=k*x + b [formula]
    
  if (phvalue > 3.8 && phvalue < 4.1){
    Serial.print("Voltage:");
    Serial.print(voltage,1);
    Serial.print("PH:");
    Serial.println(phvalue,2);

    //LCD setting 16x2
    lcd.setCursor(0,0);
    lcd.print("PH :     ");
    lcd.print(phvalue,2);

    lcd.setCursor(0,1);
    lcd.print("Volt :     ");
    lcd.print(voltage/1000,2);
    }
    else {
    Serial.begin(11520);
  // LCD Begin //
    lcd.init();
    lcd.setCursor(4,0);
    lcd.print("Dosing Required");
    delay(2000);
    lcd.clear();
  }
  }

  }


void loop2(){
  static unsigned long timepoint = millis();
  if(millis()-timepoint>1000U){
    
    timepoint = millis();
    // timepoint = read temperature 

    voltage = analogRead (PH_PIN)/4095.0*3300; 

    float slope = (7.0-4.0)/((neutralVoltage-1500)/30 - (acidVoltage-1500)/3.0);
    float intercept = 7.0 - slope*(neutralVoltage-1500)/3.0;

    phvalue = slope*(voltage-1500)/3.0 + intercept;   // y=k*x + b [formula]
    
  if (phvalue > 6.8 && phvalue < 7.1){
    Serial.print("Voltage:");
    Serial.print(voltage,1);
    Serial.print("PH:");
    Serial.println(phvalue,2);

    //LCD setting 16x2
    lcd.setCursor(0,0);
    lcd.print("PH :     ");
    lcd.print(phvalue,2);

    lcd.setCursor(0,1);
    lcd.print("Volt :     ");
    lcd.print(voltage/1000,2);
    }
    else {
    Serial.begin(11520);
  // LCD Begin //
    lcd.init();
    lcd.setCursor(4,0);
    lcd.print("Dosing Required");
    delay(2000);
    lcd.clear();
  }
}
}

void loop3 (){
  static unsigned long timepoint = millis();
  if(millis()-timepoint>1000U){
    
    timepoint = millis();
    // timepoint = read temperature 

    voltage = analogRead (PH_PIN)/4095.0*3300; 

    float slope = (7.0-4.0)/((neutralVoltage-1500)/30 - (acidVoltage-1500)/3.0);
    float intercept = 7.0 - slope*(neutralVoltage-1500)/3.0;

    phvalue = slope*(voltage-1500)/3.0 + intercept;   // y=k*x + b [formula]
    
  if (phvalue > 9.8 && phvalue < 10.1){
    Serial.print("Voltage:");
    Serial.print(voltage,1);
    Serial.print("PH:");
    Serial.println(phvalue,2);

    //LCD setting 16x2
    lcd.setCursor(0,0);
    lcd.print("PH :     ");
    lcd.print(phvalue,2);

    lcd.setCursor(0,1);
    lcd.print("Volt :     ");
    lcd.print(voltage/1000,2);
    }
    else {
    Serial.begin(11520);
  // LCD Begin //
    lcd.init();
    lcd.setCursor(4,0);
    lcd.print("Dosing Required");
    delay(2000);
    lcd.clear();
  }
  }
  }**

I am programming a ph sensor with lcd, i have tried multiple option as i needed to do alot of else/if statementdue to the requirement, however in the bolded section of my code the lcd is not showing i am unsure what i am doing wrong, is it due to a simple error?

i need to seperate out my if statement as i need it do this acion below

if phvalue range of (3.8-4.1) it will show ph : 3.8 volt: 1.68

else [ if out of range ] it will show Dosing Required

this will repeat 3 times with different value

Please do not tag spam. This has nothing to do with the ESP8266; don't use ESP8266 tags on it. — romkey, Dec 06 '22 at 18:34

score 1 · Answer 1 · answered Dec 01 '22 at 06:50

static unsigned long timepoint = millis();
if(millis()-timepoint>1000U)

Like in your last post you have a simple logical error. You save a timestamp and instantly check if one second has passed since then. This condition will never be true. That's why nothing is happening.

Why is my lcd display not showing any values?

1 Answers1