How Does The Accel 29 Click Board™ Work?
The Accel 29 Click Board™ is based on the ADXL314, a complete three-axis ±200g acceleration measurement system from Analog Devices, operating at low power levels. The ADXL314 measures both dynamic accelerations resulting from motion or shock and static accelerations, such as gravity. It provides digital output data formatted as 16-bit, with acceleration reported digitally through a configurable and selectable serial interface. The ADXL314 automatically modulates its power consumption proportionately to its output data rate. If additional power savings are desired, it also offers lower power modes, enabling intelligent motion-based power management with threshold sensing and active acceleration measurement at low power dissipation.
The ADXL314 is based on a polysilicon surface-micromachined structure built on top of a silicon wafer that suspends the structure over the surface of the wafer, providing resistance against forces due to applied acceleration. Deflection of the structure is measured using differential capacitors that consist of independent fixed plates and plates attached to the moving mass. Acceleration deflects the proof mass and unbalances the differential capacitor, producing a sensor output whose amplitude is proportional to acceleration. Phase-sensitive demodulation is used to determine the magnitude and polarity of the acceleration.
As mentioned, the acceleration data is accessed through I2C or SPI interface with a maximum frequency of 400kHz for I2C and 5MHz for SPI communication. The selection is made by positioning SMD jumpers labelled COMM SEL appropriately. 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 ADXL314 allows choosing the least significant bit (LSB) of its I2C slave address using the SMD jumper labelled ADDR SEL.
This board also possesses two interrupts, IT1 and IT2, routed to, where by default, the AN and IT pins stand on the mikroBUS™ socket, entirely programmed by the user through a serial interface. They signal MCU that a motion event has been sensed.
The Accel 29 Click Board™ can only be operated 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.
||It can be used for multiple applications, such as motion-activated functions, shock detection, high-force event detection, and more
||ADXL314 - three-axis accelerometer from Analog Devices
||±200g measurement range, low power consumption, user-selectable bandwidth, fixed 13-bit output resolution, selectable interface, embedded memory management system with FIFO technology, interrupt, and more
|Click board size
||S (28.6 x 25.4 mm)
This table shows how the pinout on f the Accel 29 Click Board™ corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).
|SPI Chip Select
|SPI Data OUT
|SPI Data IN
ONBOARD SETTINGS AND INDICATORS
||Power LED Indicator
||Communication Interface Selection SPI/I2C: Left position SPI, Right position I2C
||I2C Address Selection 0/1: Left position 0, Right position 1
ACCEL 29 CLICK ELECTRICAL SPECIFICATIONS