GY-BMP280 pressure + temperature with ESP32

Supply 3.3 V Bus I2C I2C address 0x76 / 0x77 Measures temperature, pressure

Pins and ESP32 wiring

Pin	Role	ESP32 pin	Notes
VCC	Power	3V3
GND	Ground	GND
SCL	I2C clock (SCL)	D22
SDA	I2C data (SDA)	D21
CSB	Not wired to the ESP32	—	Chip select. Leave unconnected (pulled HIGH on the board) to use I2C
SDO	Not wired to the ESP32	—	Address select: LOW = 0x76, HIGH = 0x77. Most boards default to 0x76

Suggested wiring for the 30-pin ESP32 DevKit, avoiding flash, input-only and strapping pins. BoardPilot checks it for you as you wire.

Good to know

It measures temperature and pressure only, no humidity. If your code asks for humidity, you need a BME280. (Bosch BMP280 datasheet, Product description)
The address is 0x76 with SDO to GND and 0x77 with SDO high. Most GY boards answer at 0x76, while the Adafruit library looks at 0x77 unless you pass 0x76. (Bosch BMP280 datasheet, I²C interface, slave address)

Check it is the real chip

Read register 0xD0: a genuine part answers 0x58. BoardPilot does this automatically in “Debug a problem”.

Starter code (Arduino)

#include <Wire.h>

void setup() {
  Serial.begin(115200);
  Wire.begin(21, 22);  // SDA = GPIO 21, SCL = GPIO 22
  Wire.beginTransmission(0x76);
  bool found = Wire.endTransmission() == 0;
  Serial.println(found ? "GY-BMP280 pressure + temperature found at 0x76" : "Not found: check power, GND and SDA/SCL");
}

void loop() {}

Sources

Bosch BMP280 datasheet, Register 0xD0 id (reads 0x58)
Bosch BMP280 datasheet, I2C interface: address 0x76 when SDO = GND, 0x77 when SDO = VDDIO

Try it in 3D in BoardPilot

BoardPilot Part data (JSON)

GY-BMP280 pressure + temperature on other boards: wiring and code

Arduino Mega 2560 R3 Arduino Nano Arduino Uno R3 WeAct Black Pill STM32F411CE ESP32-C3-DevKitM-1 ESP32-S3-DevKitC-1 Nordic nRF52840 DK NUCLEO-F401RE Raspberry Pi Pico 2 Raspberry Pi Pico W Raspberry Pi Pico Teensy 4.1

Learn the basics

Lesson: UART, I2C and SPI I2C I2C address SDA and SCL Pull-up resistor

Part data: CC BY 4.0, free to reuse with credit to BoardPilot.