ADXL345 Triple Axis Linear Accelerometer Module

ADXL345 Triple Axis Linear Accelerometer Module is a versatile, low-power sensor designed to measure acceleration along three axes (X, Y, and Z) with high resolution. This module incorporates the Analog Devices ADXL345 IC, a small, thin, ultralow power 3-axis accelerometer featuring a 13-bit resolution. It offers multiple measurement ranges up to ±16 g. Consequently, engineers and hobbyists select this device for accurately capturing static gravity and dynamic motion, including tilt, shock, and vibration. The ADXL345 provides flexible digital output communication through both I²C and SPI interfaces. Furthermore, its onboard features, such as tap/double-tap detection and activity/inactivity monitoring, make it an indispensable component for sophisticated motion-sensing applications and system protection.

Key Features:

• High Resolution: Offers 13-bit resolution for precise measurement of acceleration down to 4 mg/LSB, thereby ensuring high accuracy across its operating range.
• Flexible Measurement Range: User-selectable measurement ranges include ±2 g, ±4 g, ±8 g, and ±16 g, optimizing it for various tasks from simple orientation to high-impact shock detection.
• Digital Interface: Supports both standard I²C and SPI (3-wire or 4-wire) digital communication, offering broad compatibility with microcontrollers.
• Integrated Motion Features: Built-in functions detect free-fall, single-tap, double-tap, activity, and inactivity, reducing the processing load on the host MCU.
• Low Power Consumption: Features ultralow power modes suitable for battery-operated devices, drawing as little as 40 µA in standard mode.

Technical Specifications:

• Component IC: Analog Devices ADXL345
• Axes Measured: X, Y, Z (Triple Axis)
• Resolution: 13-bit (4 mg/LSB)
• Measurement Range: Selectable ±2 g, ±4 g, ±8 g, ±16 g
• Communication Protocols: I²C and SPI
• Input Voltage (V_CC): 3.0 V to 5.5 V (On-board regulator allows 5V input)
• Operating Temperature Range: −40°C to +85°C

Mechanical Specifications:

• Technology: Micro-Electro-Mechanical System (MEMS)
• Module PCB Color: Typically blue or purple
• Mounting: Standard 2.54 mm (0.1 in) pin header pitch for breadboard compatibility.
• Module Layout: Includes decoupling capacitors and necessary pull-up resistors for digital communication.

Dimensions:

• Module Board Size: ≈ 21 mm x 16 mm (May vary slightly by manufacturer)
• Pin Header Pitch: 2.54 mm
• Weight: ≈ 1.5 g (Extremely light for wearable electronics)

Pinout and Wiring:

• VCC: Connect the module to the main power supply (typically 3.3V or 5V).
• GND: Connect to the circuit ground reference.
• SCL/SCK: Serial Clock pin for I²C (SCL) or SPI (SCK) communication.
• SDA/MOSI: Serial Data pin for I²C (SDA) or SPI Master Out Slave In (MOSI).
• SDO/MISO: Serial Data Out/Master In Slave Out (MISO). This pin also controls the I²C address selection.
• CS: Chip Select pin for SPI communication (active low).
• INT1/INT2: Interrupt output pins, which consequently signal motion events like tap or activity/inactivity to the MCU.
• Wiring Note: To use I²C, connect CS to VCC and use SCL and SDA. For SPI, utilize CS, SCK, MOSI, and MISO.

Datasheet Reference:

• Download Analog Devices ADXL345 Datasheet

Commonly Used in:

• Wearable Technology: Crucial for activity monitoring, step counting, and orientation tracking in smartwatches and fitness bands.
• Drones and Robotics: Providing tilt sensing, stabilization data, and impact detection for flight controllers and robotic arms.
• Portable Devices: Used for screen rotation and power management based on device movement or lack thereof.

Applications:

• Tilt Sensing: Measuring the static angle of inclination relative to the Earth’s gravity vector.
• Vibration Monitoring: Capturing dynamic acceleration data to assess the health of machinery or structures.
• Gaming Control: Detecting movement and orientation for interactive input devices and controllers.
• Data Logger: Recording acceleration profiles for vehicle crash testing or industrial monitoring.

Equivalent Models:

• LIS3DH (STMicroelectronics): A 3-axis accelerometer offering comparable functionality and low power modes, however, its full scale range is generally lower (±2 g to ±16 g).
• MMA8452Q (NXP Semiconductors): Another low-power, high-resolution 3-axis sensor often utilized as a functional cross-reference.
• MPU6050 (Integrated Sensor): While primarily a 6-axis IMU (gyroscope + accelerometer), designers often select this IC instead for similar orientation sensing tasks.

Package Includes:

• 1 x ADXL345 Triple Axis Linear Accelerometer Module