Issue while interfacing DS18B20 with ESP32

Need Help With My Project
1

I’m trying to connect DS18B20 with ESP32 and i tried with Arduino Uno as well but in both micro-controllers I’m facing the sensor reading values it’s showing temp in serial monitor as -127°C and -196.6°F . The sensor is a new one i bought yesterday and I used a sensor which is a little older one but both of them are showing the same readings. what may be the problem?

#include <OneWire.h>
#include <DallasTemperature.h>
#include <WiFi.h>
#include <WiFiClient.h>

#define ONE_WIRE_BUS 2

OneWire oneWire(ONE_WIRE_BUS);

DallasTemperature sensors(&oneWire);

float Celsius = 0;
float Fahrenheit = 0;

void setup() {
  sensors.begin();
  Serial.begin(9600);
}

void loop() {
  sensors.requestTemperatures();

  Celsius = sensors.getTempCByIndex(0);
  Fahrenheit = sensors.toFahrenheit(Celsius);

  Serial.print(Celsius);
  Serial.print("°C");
  Serial.println(" ");
  Serial.print(Fahrenheit);
  Serial.println("°F");
  delay(5000);
}
2

-127 is the default value returned by the library when it can’t communicate with the sensor.

Pin 2 isn’t a great choice on the ESP32, as it’s a strapping oin and also has the inbuilt LED connected to it.

Does your sensor require a 4.7k pull-up resistor, or is it one of the ones that has this built in?

You don’t have any Blynk code in your sketch. I assume that you’re going to add thuis later? If you do then you can’t do this in your void loop…

Pete.

3

oh … oh, I operated DS18B20 with ESP32 without connecting it with any resistor. Because I have no idea about these resistor connecting stuffs, will it cause damage to the sensor?
Yes I don’t have Blynk code in my sketch because for my project I’m just breaking down the larger stuffs into small chunks.

4

Probably not.

Sounds like you need to research your sensor, and also the best pins to use on the ESP32.

Pete.