From an idea
to your first sensor.

YOUR NEXT SMALL SUCCESS

Where shall we start?

01 / THE BASICS

Set up your ESP32.

This guide uses a classic ESP32-WROOM development board. For an ESP32-C3 or S3, select your exact board and check its pins.

1. Install Arduino IDE.
2. Follow the official Espressif installation guide to add the ESP32 boards package.
3. Connect your board using a USB cable that carries data. Select the board and its port in the Tools menu.
4. Open a simple example, upload it and set the serial monitor to the baud rate used in Serial.begin.

02 / SENSORS

Your first temperature reading.

Goal: read a three-wire, externally powered DS18B20 using a classic ESP32 development board. No account or Wi-Fi connection is required.

Gather the parts

An ESP32, a DS18B20, a 4.7 kΩ resistor, a breadboard, jumper wires and a USB data cable.

Connect the sensor

Disconnect USB before wiring. Identify VDD, DQ and GND using your sensor documentation. Probe wire colours alone do not guarantee the pinout.

Upload the program

In Arduino Library Manager, install OneWire by Paul Stoffregen and DallasTemperature by Miles Burton. Select your ESP32 and its port, then upload this code.

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

constexpr uint8_t SENSOR_PIN = 4;
OneWire oneWire(SENSOR_PIN);
DallasTemperature sensors(&oneWire);

void setup() {
  Serial.begin(115200);
  sensors.begin();
}

void loop() {
  sensors.requestTemperatures();
  float temperature = sensors.getTempCByIndex(0);
  if (temperature == DEVICE_DISCONNECTED_C) {
    Serial.println("Sensor not found: check the wiring.");
  } else {
    Serial.print("Temperature: ");
    Serial.print(temperature, 2);
    Serial.println(" deg C");
  }
  delay(2000);
}

Watch your first reading

Open the serial monitor at 115200 baud. A new reading appears roughly every three seconds, including conversion time. Gently warm the probe between your fingers and watch the value change.

03 / UNDERSTAND THE RESULT

An unexpected reading?

Displaying two decimal places does not guarantee an accuracy of 0.01 °C. Consult the manufacturer’s data sheet to distinguish resolution from accuracy.