Description
The ADXL345 is a compact, low-power 3-axis digital accelerometer capable of measuring acceleration in the ±2g to ±16g range with 13-bit resolution. Ideal for motion sensing, tilt detection, and vibration monitoring, it supports both I2C and SPI communication interfaces, making it versatile and easy to integrate with a wide range of microcontrollers including Arduino, STM32, ESP32, and Raspberry Pi.
With a sensitivity of 4mg/LSB and the ability to detect as little as 0.25° changes in inclination, this module is perfect for applications involving orientation sensing, fall detection, activity/inactivity monitoring, and general motion detection in embedded systems.
Its onboard digital interface supports SPI (3- or 4-wire) and I2C, and outputs data in 16-bit two’s complement format, making it robust and ready for real-time motion capture in mobile, wearable, and industrial systems.
✅ Key Features
3-Axis Acceleration Measurement (X, Y, Z)
Measuring Range: ±2g, ±4g, ±8g, ±16g (configurable)
Compact & Thin Design – Ideal for space-limited systems
I2C or SPI Interface – 3- or 4-wire SPI supported
Digital Output in 16-bit Two’s Complement Format
⚡ Low Power Consumption – Great for portable devices
️ Activity/Inactivity Detection – Based on user-defined threshold
Tilt and Free-Fall Sensing – Perfect for motion or fall detection systems
High Sensitivity: 4mg/LSB
Adjustable data rates and interrupt configurations
Technical Specifications
| Parameter | Value |
|---|---|
| Input Voltage | 3V to 5V DC |
| Interface | I2C / SPI (3 or 4 wire) |
| Output Format | 16-bit 2’s complement |
| Resolution | 13-bit, 4mg/LSB |
| Measuring Range | ±2g, ±4g, ±8g, ±16g |
| Operating Temperature | −40°C to +85°C |
| Module Type | 3DOF accelerometer (digital) |
| Sensitivity | ~0.25° inclination detection |
| Dimensions | Compact breakout board (~20x20mm) |
⚙️ Applications
Tilt sensing and orientation detection
Motion and vibration analysis
Free-fall detection in safety systems
Wearable device accelerometers
Activity/inactivity sensing in fitness trackers
Robotics balance control
Drone stabilization and feedback
FAQ – Frequently Asked Questions
Q1: Can I use ADXL345 with Arduino?
✅ Yes, it’s fully compatible. Libraries like Adafruit ADXL345 or Wire + SPI can be used.
Q2: What communication protocol does it use?
It supports both I2C and SPI. You can choose based on your microcontroller.
Q3: Can it detect free fall or motion?
✅ Yes! It supports free-fall detection, activity/inactivity sensing, and user-set acceleration thresholds.
Q4: Does this module include pull-up resistors for I2C?
⚠️ Not always. You may need to add external pull-ups depending on your platform.
Q5: Is it suitable for wearable motion sensing?
✅ Absolutely. It has low power usage and high sensitivity ideal for battery-powered, wearable applications.
