BMP180 Pressure Sensor Module
🧠 What Is BMP180?
A digital barometric pressure sensor used to measure atmospheric pressure and temperature.
Based on piezoresistive MEMS technology for accurate pressure sensing.
Commonly used for altitude measurement and weather monitoring.
🔍 Key Features
Measures Pressure & Temperature
High Accuracy & Resolution
Digital Output (I²C interface)
Low Power Consumption
Compact and lightweight module
Factory calibrated with internal coefficients
📊 Technical Specifications
| Parameter | Value |
|---|---|
| Operating Voltage | 3.3 V (some modules include regulator for 5 V use) |
| Pressure Range | 300 – 1100 hPa |
| Altitude Range | ~0 to 9000 meters |
| Temperature Range | –40 °C to +85 °C |
| Pressure Accuracy | ±1 hPa (~±8 m altitude) |
| Resolution | Up to 0.01 hPa |
| Interface | I²C (2-wire) |
⚙️ Pin Configuration
VCC → 3.3V (or 5V if module has regulator)
GND → Ground
SCL → I²C Clock
SDA → I²C Data
📌 Some modules also include:
XCLR / EOC pins (rarely used in basic setups)
🧠 How It Works
The sensor measures atmospheric pressure using a MEMS sensing element.
Internal ADC converts pressure and temperature into digital values.
Calibration data stored in the sensor improves accuracy.
Microcontroller reads values via I²C communication.
Altitude is calculated using pressure differences.
📌 Applications
Weather stations
Altitude measurement (drones, GPS assist)
Indoor navigation systems
IoT environmental monitoring
Smart devices (fitness, climbing, etc.)
🧪 Altitude Calculation
Altitude is derived from pressure using:
Lower pressure → Higher altitude
Formula (simplified):
Altitude ≈ function of pressure difference from sea level
⚠️ Important Notes
Not Waterproof: Must be protected from moisture.
Sensitive to Temperature Changes: Always use temperature compensation.
3.3V Logic: Check module level shifting if using 5V boards.
Better Alternatives: BMP280, BME280 (higher accuracy, humidity support).
🛠 Summary
Type: Digital barometric pressure + temperature sensor
Interface: I²C
Use Case: Altitude & weather monitoring
Advantage: High resolution, low power
