ESP8266 - Temperature Sensor - OLED

This tutorial instructs you how to use ESP8266 to read the temperature from a DS18B20 sensor and then display it on an OLED.

Hardware Preparation

1×ESP8266 NodeMCU
1×Micro USB Cable
1×SSD1306 I2C OLED Display 128x64
1×DS18B20 Temperature Sensor (WITH Adapter)
1×DS18B20 Temperature Sensor (WITHOUT Adapter)
1×Breadboard
1×Jumper Wires
1×(Optional) 5V Power Adapter for ESP8266
1×(Optional) ESP8266 Screw Terminal Adapter

Or you can buy the following sensor kits:

1×DIYables Sensor Kit (30 sensors/displays)
1×DIYables Sensor Kit (18 sensors/displays)
Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you. We appreciate your support.

Buy Note: Many DS18B20 sensors available in the market are unreliable. We strongly recommend buying the sensor from the DIYables brand using the link provided above. We tested it, and it worked reliably.

Overview of OLED and DS18B20 Temperature Sensor

If you are unfamiliar with OLED and DS18B20 Temperature Sensor (pinout, functionality, programming, etc.), the following tutorials can help:

Wiring Diagram

The wiring diagram between ESP8266 NodeMCU and DS18B20 Temperature Sensor OLED

This image is created using Fritzing. Click to enlarge image

See more in ESP8266's pinout and how to supply power to the ESP8266 and other components.

We recommend buying a DS18B20 sensor along with its accompanying wiring adapter for a seamless setup. This adapter includes an integrated resistor, removing the need for an additional resistor in the wiring.

ESP8266 Code - Temperature from DS18B20 Temperature Sensor and display it on OLED

/* * This ESP8266 NodeMCU code was developed by newbiely.com * * This ESP8266 NodeMCU code is made available for public use without any restriction * * For comprehensive instructions and wiring diagrams, please visit: * https://newbiely.com/tutorials/esp8266/esp8266-temperature-sensor-oled */ #include <Wire.h> #include <Adafruit_GFX.h> #include <Adafruit_SSD1306.h> #include <OneWire.h> #include <DallasTemperature.h> #define OLED_WIDTH 128 // OLED display width, in pixels #define OLED_HEIGHT 64 // OLED display height, in pixels #define SENSOR_PIN 2 // The ESP8266 pin connected to DS18B20 sensor's DQ pin Adafruit_SSD1306 oled(OLED_WIDTH, OLED_HEIGHT, &Wire, -1); // create SSD1306 display object connected to I2C OneWire oneWire(SENSOR_PIN); // setup a oneWire instance DallasTemperature DS18B20(&oneWire); // pass oneWire to DallasTemperature library String temperature_str; void setup() { Serial.begin(9600); // initialize OLED display with address 0x3C for 128x64 if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { Serial.println(F("SSD1306 allocation failed")); while (true); } delay(2000); // wait for initializing oled.clearDisplay(); // clear display oled.setTextSize(2); // text size oled.setTextColor(WHITE); // text color oled.setCursor(0, 10); // position to display DS18B20.begin(); // initialize the sensor temperature_str.reserve(10); // to avoid fragmenting memory when using String } void loop() { DS18B20.requestTemperatures(); // send the command to get temperatures float temperature_C = DS18B20.getTempCByIndex(0); // read temperature in Celsius temperature_str = String(temperature_C, 2); // two decimal places temperature_str += "°C"; Serial.println(temperature_str); // print the temperature in Celsius to Serial Monitor oled_display_center(temperature_str); } void oled_display_center(String text) { int16_t x1; int16_t y1; uint16_t width; uint16_t height; oled.getTextBounds(text, 0, 0, &x1, &y1, &width, &height); // center the display both horizontally and vertically oled.clearDisplay(); // clear display oled.setCursor((OLED_WIDTH - width) / 2, (OLED_HEIGHT - height) / 2); oled.println(text); // text to display oled.display(); }

Detailed Instructions

To get started with ESP8266 on Arduino IDE, follow these steps:

  • Check out the how to setup environment for ESP8266 on Arduino IDE tutorial if this is your first time using ESP8266.
  • Wire the components as shown in the diagram.
  • Connect the ESP8266 board to your computer using a USB cable.
  • Open Arduino IDE on your computer.
  • Choose the correct ESP8266 board, such as (e.g. NodeMCU 1.0 (ESP-12E Module)), and its respective COM port.
  • Click to the Libraries icon on the left bar of the Arduino IDE.
  • Search for “SSD1306” and locate the SSD1306 library by Adafruit.
  • Then, press the Install button to complete the installation.
ESP8266 NodeMCU OLED library
  • You will be prompted to install additional library dependencies.
  • To install all of them, click the Install All button.
ESP8266 NodeMCU Adafruit GFX sensor library
  • Search for “Dallas” and locate the DallasTemperature library by Miles Burton.
  • Press the Install button to install the DallasTemperature library.
ESP8266 NodeMCU Dallas Temperature library
  • You will be asked to install the dependency. Click Install All button to install OneWire library.
ESP8266 NodeMCU onewire library
  • Copy the code and open it in the Arduino IDE.
  • Click the Upload button to transfer the code to your ESP8266.
  • Place the sensor in hot and cold water, or hold it in your hand.
  • Check out the result on the OLED.

※ NOTE THAT:

The code in question will center the text both horizontally and vertically on an OLED display.

Video Tutorial

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