GY-63 MS5611-01BA03 high-precision pressure sensor module

Pinout & Interface Guide

The GY-63 module features a 6-pin configuration for flexible communication interface selection. Pin labeling may vary slightly between manufacturers; always verify the silkscreen on your specific board .

Pin Definitions

Communication Mode Selection

I²C Address Configuration:

• When CSB is HIGH (connected to VCC), the I²C address is 0x76 (or 0x77 depending on module variant) 

• When CSB is LOW (connected to GND), the I²C address is 0x76 (or 0x77) 

Wiring Diagram (I²C Mode – Recommended for Simplicity)

For Arduino Uno / Nano:

For ESP32 / ESP8266:

Important Note: For I²C mode, ensure pull-up resistors (typically 4.7kΩ) are present on the SCL and SDA lines. Most GY-63 modules include these onboard, but verify your specific board .

Theory of Operation

Pressure-to-Altitude Relationship

Atmospheric pressure decreases with increasing altitude. The MS5611 measures absolute barometric pressure, from which altitude can be calculated using the barometric formula. The high resolution of the sensor (up to 0.012 mbar) enables altitude detection with approximately 10 cm resolution .

Oversampling (OSR)

The MS5611 supports multiple Oversampling Ratio (OSR) settings that trade off between conversion speed and noise level :

Higher OSR settings provide better noise reduction and resolution but require longer conversion times. For altitude measurement applications requiring centimeter-level accuracy, OSR_HIGH or OSR_ULTRA_HIGH are recommended.

Temperature Compensation

The MS5611 includes an integrated temperature sensor that is used to compensate the pressure readings. The 24-bit ADC simultaneously measures both pressure and temperature, and the factory-stored calibration coefficients are applied to obtain accurate, temperature-compensated results .

Usage Guide

Software Setup (Arduino IDE)

Step 1: Install Required Libraries

Several libraries support the MS5611 sensor. The most commonly used are:

Option A: “MS5611” Library (by Rob Tillaart) – Most versatile, supports both I²C and SPI 

Option B: “Adafruit MS5611” Library – Simple, well-documented

Option C: “MS561101BA” Library – Older but stable library

Install via Arduino Library Manager:

1. Open Arduino IDE → Sketch → Include Library → Manage Libraries

2. Search for “MS5611”

3. Install the library by Rob Tillaart (recommended) or Adafruit 

Step 2: Basic Test Sketch (I²C Mode)

/*
  GY-63 MS5611 High-Precision Pressure Sensor Example
  Reads pressure, temperature, and calculates altitude
*/

#include <Wire.h>
#include <MS5611.h>

// Create MS5611 object (I2C address 0x76 default)
// If using address 0x77, change to MS5611(0x77)
MS5611 sensor(0x76);

// Constants for altitude calculation
const float SEA_LEVEL_PRESSURE = 1013.25;  // hPa at sea level

void setup() {
  Serial.begin(115200);
  Wire.begin();
  
  // Initialize the sensor
  if (!sensor.begin()) {
    Serial.println("MS5611 sensor not found! Check wiring.");
    while (1);
  }
  
  Serial.println("GY-63 MS5611 Sensor Ready");
  Serial.println("-----------------------------");
  
  // Optional: Set oversampling rate for higher precision
  // sensor.setOversampling(OSR_ULTRA_HIGH);  // Maximum precision
}

void loop() {
  // Read pressure and temperature
  // This command triggers a conversion and reads the result
  // The sensor reads both pressure and temperature simultaneously
  sensor.read();
  
  // Get pressure in millibars (hPa)
  float pressure = sensor.getPressure();
  
  // Get temperature in degrees Celsius
  float temperature = sensor.getTemperature();
  
  // Calculate altitude in meters using the barometric formula
  float altitude = 44330.0 * (1.0 - pow(pressure / SEA_LEVEL_PRESSURE, 0.1903));
  
  // Display results
  Serial.print("Pressure: ");
  Serial.print(pressure);
  Serial.println(" hPa");
  
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" °C");
  
  Serial.print("Altitude: ");
  Serial.print(altitude);
  Serial.println(" m");
  
  Serial.println("-----------------------------");
  
  delay(1000);  // Read once per second
}

Step 3: Manual Read of Calibration Coefficients (For Advanced Users)

The MS5611 stores 6 factory calibration coefficients (C1 to C6) in its PROM. These are used to convert raw ADC readings to actual pressure and temperature values .

#include <Wire.h>

#define MS5611_ADDR 0x76

void readCalibrationCoefficients() {
  Wire.beginTransmission(MS5611_ADDR);
  Wire.write(0x1E);  // Reset command
  Wire.endTransmission();
  delay(10);
  
  // Read 6 calibration coefficients (each is 16-bit)
  for (int i = 1; i <= 6; i++) {
    Wire.beginTransmission(MS5611_ADDR);
    Wire.write(0xA0 + (i * 2));  // PROM read address for coefficient i
    Wire.endTransmission();
    
    Wire.requestFrom(MS5611_ADDR, 2);
    uint16_t coeff = Wire.read() << 8 | Wire.read();
    
    Serial.print("C");
    Serial.print(i);
    Serial.print(": ");
    Serial.println(coeff);
  }
}

Using with Different Microcontrollers

Arduino (5V Logic):

• Connect VCC to 5V (onboard regulator steps down to 3.3V)

• SCL/SDA connect directly to I²C pins (A5/A4 on Uno) 

ESP32 / ESP8266 (3.3V Logic):

• Connect VCC to 3.3V

• Connect SCL/SDA to appropriate I²C pins

• The sensor works well with both 3.3V and 5V logic 

Raspberry Pi (Python):

• Enable I²C via raspi-config

• Install required libraries: pip3 install adafruit-circuitpython-ms5611 

• Connect VCC to 3.3V (Pin 1), GND to GND, SCL to GPIO3 (Pin 5), SDA to GPIO2 (Pin 3)

Altitude Calculation Tips

For accurate altitude readings, you should provide the local sea-level pressure. This can be obtained from:

• Local weather station data

• GPS altitude reference at a known location

• Initial calibration at a known altitude

// Correct altitude calculation using local sea-level pressure
float calculateAltitude(float measuredPressure, float seaLevelPressure) {
  // Formula: alt = 44330 * (1 - (P/P0)^(1/5.255))
  return 44330.0 * (1.0 - pow(measuredPressure / seaLevelPressure, 0.1903));
}