Sensors / DHT22 Sensor

Build a Weather Beacon

Read live climate data and show it beautifully on a compact OLED so your first IoT dashboard feels instantly useful.

Intermediate 34 min By Ruth Tembo

What you will learn

• Turn it into a room comfort monitor with color-coded humidity warnings.
• Add buzzer or LED alerts when temperature crosses a greenhouse threshold.

Components

Community Tips

ESP32 Weather Beacon with OLED Display

CircuitSpark Lab • 42.2K views • Mar 02, 2026

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Intermediate 34 min Sensors Community Maker: Ruth Tembo

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Build Guide

Step-by-Step Instructions

Step 1 of 3

Step 1

Wire the ESP32, sensor, and display

Connect the DHT22 to 3.3V, ground, and one data pin. Then connect the OLED using the ESP32 I2C pins so the screen can share the bus cleanly.

Use consistent jumper colors for power and signal lines. That small discipline prevents almost every early wiring mistake.

Wire the ESP32, sensor, and display — Keep your power rails short and label SDA and SCL early.

Step 2

Install the libraries and verify addresses

Install the DHT and SSD1306 libraries, then run a basic I2C scanner if the display does not respond immediately.


#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

Adafruit_SSD1306 display(128, 64, &Wire, -1);

void setup() {
  Wire.begin();
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.setCursor(0, 0);
  display.println("Weather Beacon");
  display.display();
}

Most small OLED screens use address 0x3C, but some modules ship as 0x3D. Confirm before blaming the library.

Install the libraries and verify addresses — A quick I2C scan saves minutes of confusion later.

Step 3

Render a compact dashboard

Display temperature and humidity with enough spacing that the values can be read across a room.

Once the numbers are stable, experiment with icons, trend arrows, or a comfort label so the project feels closer to a real product than a raw prototype.