BME280 on OLED: Temp, Humidity & Pressure
Overview & Wiring
What it is: The BME280 is the BMP280's bigger sibling — it adds humidity, so you get temperature, humidity and barometric pressure from one tiny I2C chip. It's the go-to sensor for weather stations.
How it works: Identical wiring to the BMP280 (I2C, shared with the OLED). The Adafruit library returns all three calibrated values.
Wiring (shared I2C bus with the OLED):
BME280 SDA -> GPIO4
BME280 SCL -> GPIO5
BME280 VCC -> 3V3
BME280 GND -> GND
OLED VCC=3V3, GND=GND, SDA=GPIO4, SCL=GPIO5
Libraries: "Adafruit BME280 Library" (installs "Adafruit BusIO" and "Adafruit Unified Sensor"), plus "Adafruit SSD1306" and "Adafruit GFX Library".
On screen / Serial: three lines — temperature (°C), humidity (%), pressure (hPa).
Gotchas: Beware fake modules labelled BME280 that are actually BMP280 (no humidity — humidity reads 0 or a fixed number). Address is usually 0x76, sometimes 0x77; the code tries both.
Circuit Diagram
Parts You Need
Source Code (Arduino / ESP32)
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_BME280.h>
Adafruit_SSD1306 display(128, 64, &Wire, -1);
Adafruit_BME280 bme;
void setup() {
Serial.begin(115200);
Wire.begin(4, 5);
display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
if (!bme.begin(0x76) && !bme.begin(0x77)) {
Serial.println("BME280 not found");
display.setTextColor(SSD1306_WHITE);
display.setCursor(0, 28); display.println("BME280 not found");
display.display();
while (1) delay(10);
}
}
void loop() {
float t = bme.readTemperature(); // °C
float h = bme.readHumidity(); // %
float hpa = bme.readPressure() / 100.0; // hPa
display.clearDisplay();
display.setTextColor(SSD1306_WHITE);
display.setTextSize(1);
display.setCursor(0, 0); display.println("BME280");
display.setCursor(0, 16); display.printf("Temp: %.1f C", t);
display.setCursor(0, 32); display.printf("Hum : %.0f %%", h);
display.setCursor(0, 48); display.printf("Pres: %.0f hPa", hpa);
display.display();
Serial.printf("T %.1fC H %.0f%% P %.0fhPa\n", t, h, hpa);
delay(1000);
}