Sketch not working correctly

Projects Programming
1

Sketch is copied from the web. I would think who ever posted in would make Shure it worked.
Need help, Back light lights up, but no numbers are displayed. Simple wiring so Iam Shure it is wired correctly. Tried another sketch to test display and it worked.
Iam new to this need a lot of help.

                                                                                                Thanks Jeff 

#include <LiquidCrystal_I2C.h>


#include <DallasTemperature.h>

#include <OneWire.h>

/*
   Created by ArduinoGetStarted.com

   This example code is in the public domain

   Tutorial page: https://arduinogetstarted.com/tutorials/arduino-temperature-sensor-lcd
*/



const int SENSOR_PIN = 2; // Arduino pin connected to DS18B20 sensor's DQ pin

OneWire oneWire(SENSOR_PIN);         // setup a oneWire instance
DallasTemperature sensors(&oneWire); // pass oneWire to DallasTemperature library
LiquidCrystal_I2C lcd(0x3F, 16, 2);  // I2C address 0x27, 16 column and 2 rows

float tempCelsius;    // temperature in Celsius
float tempFahrenheit; // temperature in Fahrenheit

void setup()
{
  sensors.begin();    // initialize the sensor
  lcd.init();         // initialize the lcd
  lcd.backlight();    // open the backlight
}

void loop()
{
  sensors.requestTemperatures();             // send the command to get temperatures
  tempCelsius = sensors.getTempCByIndex(0);  // read temperature in Celsius
  tempFahrenheit = tempCelsius * 9 / 5 + 32; // convert Celsius to Fahrenheit

  lcd.clear();
  lcd.setCursor(0, 0);       // start to print at the first row
  lcd.print(tempCelsius);    // print the temperature in Celsius
  lcd.print((char)223);      // print ° character
  lcd.print("C");
  lcd.setCursor(0, 1);       // start to print at the second row
  lcd.print(tempFahrenheit); // print the temperature in Fahrenheit
  lcd.print((char)223);      // print ° character
  lcd.print("F");

  delay(500);
}
2

Hi would you mind to post the sketch that worked? It might help to find the relevant difference.

3

That's a very sweet sentiment, but there's an awful lot of hardware out there that may be incompatible, and there's no way anyone will have tested it all

4

Here is the sketch>

                         Thanks Jeff

/*
   Created by ArduinoGetStarted.com

   This example code is in the public domain

   Tutorial page: https://arduinogetstarted.com/tutorials/arduino-temperature-humidity-sensor-lcd
*/

#include <LiquidCrystal_I2C.h>
#include "DHT.h"
#define DHTPIN 2
#define DHTTYPE DHT11

LiquidCrystal_I2C lcd(0x3F, 16, 2);  // I2C address 0x3F, 16 column and 2 rows
DHT dht(DHTPIN, DHTTYPE);

void setup()
{
  dht.begin();     // initialize the sensor
  lcd.init();      // initialize the lcd
  lcd.backlight(); // open the backlight
}

void loop()
{
  delay(2000); // wait a few seconds between measurements

  float humi  = dht.readHumidity();    // read humidity
  float tempC = dht.readTemperature(); // read temperature

  lcd.clear();
  // check if any reads failed
  if (isnan(humi) || isnan(tempC)) {
    lcd.setCursor(0, 0);
    lcd.print("Failed");
  } else {
    lcd.setCursor(0, 0);  // start to print at the first row
    lcd.print("Temp: ");
    lcd.print(tempC);     // print the temperature
    lcd.print((char)223); // print ° character
    lcd.print("C");

    
  lcd.setCursor(0, 1);  // start to print at the second row
    lcd.print("Humi: ");
    lcd.print(humi);      // print the humidity
    lcd.print("%");
  }
}
5

Did your LCD "hello world" sketch work as expected?