GY-68 BMP180 pressure + temperature with ESP32

Supply 3.3-5 V Bus I2C I2C address 0x77 Measures temperature, pressure

Pins and ESP32 wiring

Pin	Role	ESP32 pin
VIN	Power	3V3
GND	Ground	GND
SCL	I2C clock (SCL)	D22
SDA	I2C data (SDA)	D21

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

Check it is the real chip

Read register 0xD0: a genuine part answers 0x55. 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(0x77);
  bool found = Wire.endTransmission() == 0;
  Serial.println(found ? "GY-68 BMP180 pressure + temperature found at 0x77" : "Not found: check power, GND and SDA/SCL");
}

void loop() {}

Sources

Bosch BMP180 datasheet, Memory map: register 0xD0 chip id (fixed value 0x55)
Bosch BMP180 datasheet, I2C interface: module address 0xEE write / 0xEF read (7-bit 0x77)

Try it in 3D in BoardPilot

BoardPilot Part data (JSON)

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