MIKROE Accel 14 Click

Accel 14 Click is digital acceleration and vibration sensor Click board™. It features an ultra-wide bandwidth, low-noise, 3-axis digital vibration sensor, labeled as IIS3DWB, from STMicroelectronics. This Click board™ allows selectable full-scale acceleration measurements in ranges of ±2 g, ±4 g, ±8, and ±16 g in three axes, and it’s capable of measuring accelerations with a bandwidth up to 6 kHz with an output data rate of 26.7 kHz. For accessing sensor registers from any host controller communication is accomplished through a standard SPI serial interface. Along with its serial interface, the sensor can use any of its two interrupt pins to report a detected event. It has many features that make it attractive for various applications such as vibration and condition monitoring, test and measurements, predictive maintenance, and more.

Accel 14 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

Accel 14 Click uses the IIS3DWB IC, an ultra-wide bandwidth, low-noise, 3-axis digital vibration sensor from STMicroelectronics. The wide bandwidth, low noise, very stable and repeatable sensitivity, together with the capability of operating over an extended temperature range, makes this device particularly suitable for vibration monitoring in industrial applications. The IIS3DWB has a selectable full-scale acceleration range of ±2/±4/±8/±16 g and is capable of measuring accelerations with a bandwidth up to 6 kHz with an output data rate of 26.7 kHz. A 3 kB first-in, first-out (FIFO) buffer is integrated into the device to avoid any data loss and to limit the intervention of the host processor.

Accel 14 Click offers two possible operating configurations: Power-Down and Normal Mode. IIS3DWB has a voltage supply range from 2.1V to 3.6V. To avoid potential conflicts, during the power-on sequence, it is recommended to set the lines connected to the device IO pins to high-impedance state on the host side. Furthermore, to guarantee the proper power-off of the device, it is recommended to maintain the duration of the VDD line to GND for at least 100 μs. After the power supply is applied, the IIS3DWB performs a 10 ms boot procedure to load the trimming parameters.

After the boot is completed, the accelerometer is automatically configured in Power-Down mode. When the sensor is in Power-Down mode, almost all internal blocks of the device are switched off. The SPI digital interface remains active to allow communication with the device. The content of the configuration registers is preserved and the output data registers are not updated, keeping the last data sampled in memory before going into Power-Down mode.

When Accel 14 Click is set in Normal Mode, all three axes (X, Y, Z) are simultaneously active and acceleration data can be read from the sensor concurrently for the 3-axis and the sensor provides acceleration data at an output data rate of 26.667kHz.

The IIS3DWB has been specifically designed to provide a wide bandwidth with very flat frequency response in the passband and very high attenuation in the stopband so to virtually eliminate any frequency aliasing. The functionality of the device and the measured acceleration data is accessible through the SPI interface. And also functions such as the threshold and the timing of the two interrupt pins can be completely programmed by the user through the SPI digital interface.

This Click board™ is designed to be operated only with 3.3V logic levels. A proper logic voltage level conversion should be performed before the Click board™ is used with MCUs with logic levels of 5V. More information about the IIS3DWB can be found in the attached datasheet. However, the Click board™ comes equipped with a library that contains easy to use functions and a usage example that may be used as a reference for the development.

• Interface: GPIO, SPI
• Compatibility: mikroBUS™
• Dimensions: 28.6 x 25.4mm
• Input Voltage: 3.3V
• Supply Voltage: Min. 2.1V, Max. 3.6V
• Accelerometer current consumption: Typ. 1.1mA, Max. 1.3mA
• SPI clock frequency: 10 mHz
• Operating Temperature Range: Min. -40°C, Max. +105°C