ADXL355 DIGITAL ACCELEROMETER¶
Introduction¶
Acceleration measurement is a common requirement in many embedded systems. The ADXL355 is a high-precision, low-power, three-axis digital accelerometer suitable for various applications such as motion detection, tilt measurement, and vibration monitoring.
The ADXL355 features low noise density, high resolution, and a wide measurement range, making it ideal for applications requiring accurate and reliable acceleration data.
Key Features (Summary)¶
- Low Noise: Typical noise density of approximately 22.5 µg/√Hz (all axes)
- Low Temperature Drift: 0 g offset variation with temperature ≤ 0.15 mg/°C (all axes)
- Low Power Consumption: Measurement mode approximately 200 µA; standby approximately 21 µA
- Selectable Measurement Ranges: ±2 g, ±4 g, ±8 g (model/configuration dependent)
- Interface: SPI and I2C (digital output)
- High Resolution: Built-in 20-bit ADC, supports synchronous sampling and data interpolation
- Programmable Digital Filtering: Supports high/low-pass digital filtering
- Integrated Temperature Sensor and Self-Test Functionality
- Supply Voltage: 2.25 V to 3.6 V (with internal regulator enabled); typically 1.8 V ±10% when bypassing internal LDO
- Operating Temperature: -40°C to +125°C
- Package: 14-lead LCC, approximately 6.0 × 5.6 × 2.2 mm
Typical Applications¶
- Inertial Measurement Units (IMU), Attitude and Heading Reference Systems (AHRS)
- Platform Stabilization and Motion Compensation
- Structural Health Monitoring and Vibration Analysis
- Seismic/Shock Detection and Imaging
- Tilt Sensing, Robotics, IoT Sensor Nodes, and Condition Monitoring
Technical Specifications (Summary Table)¶
| Parameter | Specification / Description |
|---|---|
| Measurement Range | ±2 g, ±4 g, ±8 g (selectable) |
| Resolution | 20 bit (ADXL355) |
| Noise Density | Approximately 22.5 µg/√Hz (typical) |
| Interface | SPI, I2C (ADXL355) |
| Operating Voltage | 2.25 V to 3.6 V (with internal regulator) |
| Operating Temperature | -40°C to +125°C |
DMA Support Note¶
DMA Configuration
In this implementation, the ADXL355 driver uses the SPI3 bus for communication, which has DMA enabled (SPI_DMA_CH_AUTO). Enabling DMA provides the following benefits:
- Reduced CPU Usage: SPI data transfers are automatically handled by the DMA controller, freeing the CPU from data transfer operations
- Improved Transfer Performance: Especially beneficial for ADXL355's high-frequency sampling scenarios (up to 4000 Hz output data rate)
- Automatic Usage: Once DMA is enabled during SPI bus initialization, all SPI transactions (including
spi_device_polling_transmit()) automatically use DMA without additional configuration
The initialization process will output log messages confirming that DMA is enabled, and all SPI read/write operations will automatically utilize DMA for data transfer.
Evaluation Board¶
Wiring¶
As shown in the figure, this project uses SPI wiring for the ADXL355 and connects it to the ESP32-S3 SPI3 bus.
| ADXL355 Evaluation Board Pin | Abbreviation | Function | Corresponding MCU Pin | Description |
|---|---|---|---|---|
| PIN 1 | CS | Chip select | GPIO 7 | SPI chip select signal |
| PIN 2 | MOSI | Master out, slave in | GPIO 16 | SPI master output / slave input |
| PIN 3 | MISO | Master in, slave out | GPIO 17 | SPI master input / slave output |
| PIN 4 | SCK | Clock | GPIO 15 | SPI clock signal |
| PIN 5 | DGND | Digital ground | GND | Digital ground connection |
| PIN 6 | VDD | Supply voltage | 3.3 V | Supply voltage connection |
| PIN 7 | INT1 | Interrupt output | GPIO 4 | Optional interrupt output connection |
| PIN 8 | NC | Not connected | Floating | Not connected |
| PIN 9 | INT2 | Interrupt output | GPIO 5 | Optional interrupt output connection |
| PIN 10 | DRDY | Data ready output | GPIO 6 | Optional data-ready signal connection |
| PIN 11 | DGND | Digital ground | GND | Digital ground connection |
| PIN 12 | VDD | Supply voltage | 3.3 V | Supply voltage connection |
Official Driver Reference¶
-
ADXL355 Driver
ADXL355