Accel 4 Click is a compact add-on board that contains an acceleration sensor. This board features the FXLS8974CF, a 12-bit three-axis accelerometer from NXP Semiconductors. It allows selectable full-scale acceleration measurements in ranges of ±2g, ±4g, ±8g, or ±16g in three axes with a configurable host interface that supports both SPI and I2C serial communication. The FXLS8974CF supports both high-performance and low-power operating modes, allowing maximum flexibility to meet the resolution and power needs for various unique use cases. This Click board™ is suitable for a wide range of automotive (convenience and security), industrial, and medical IoT applications that require ultra-low-power Wake-Up on the motion.

Accel 4 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

NOTE: This Click board™, alongside FXLS8974CF, also represents a reference design for the FXLS8964AF and FXLS8967AF.

Accel 4 Click as its foundation uses the FXLS8974CF, a highly reliable digital triaxial acceleration from NXP Semiconductors. The FXLS8974CF is highly configurable with a programmable acceleration range of ±2g, ±4g, ±8g, or ±16g, capable of measuring accelerations with selectable output data rates. It supports high-performance and low-power operating modes, allowing maximum flexibility to meet the resolution and power needs for various use cases from automotive (convenience and security) through industrial IoT to some consumer devices.

This sensor includes advanced digital features such as the SDCD block for inertial event detection, auto wake-sleep, and a 32 sample FIFO/LIFO buffer. Besides, it has an embedded temperature sensor with an 8 bits resolution, sensitivity of 1°C/LSB, and measurement range from -40°C up to +105°C. Selectable ODRs (Output Data Rate) of the FXLS8974CF go up to 3200Hz, alongside Flexible Performance mode, allowing custom ODRs with a programmable decimation (resolution) and idle-time settings.

Accel 4 Click allows using both I2C and SPI interfaces with a maximum frequency of 1MHz for I2C and 4MHz for SPI communication. The selection can be made by positioning SMD jumpers labeled as COMM SEL in an appropriate position. Note that all the jumpers' positions must be on the same side, or the Click board™ may become unresponsive. While the I2C interface is selected, the FXLS8974CF allows choosing the least significant bit (LSB) of its I2C peripheral address using the SMD jumper labeled ADDR SEL.

The FXLS8974CF also possesses two interrupts, INT1 and INT2, routed to the INT and AN pins on the mikroBUS™ socket used to signal MCU that an event has been sensed, entirely programmed by the user through the I2C/SPI interface. Also, this Click board™ provides the ability to use the boot mode of the FXLS8974CF by positioning SMD jumpers labeled as BT MODE to an appropriate position. Depending on the selected position, the device can be set in the default operating mode by setting the jumper to position 0 or in Motion Detection Mode to position 1.

This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

• Interface: I²C, SPI
• Compatibility: mikroBUS™
• Dimensions: 28.6 x 25.4mm
• Input Voltage: 3.3V
• Acceleration Range: Min. ±2g, Max. ±16g
• Acceleration Resolution: 12 bits
• Sensitivity (±2 ~ ±16): Min. 128 LSB/g, Max. 1024 LSB/g
• Operating Temperature Range: Min. -40°C, Typ. +25°C, Max. +105°C

• Schematic
• FXLS8974CF Datasheet
• mikroSDK
• GitHub