HOW DOES IT WORK?

Accel 16 Click as its foundation uses the ADXL363, a micropower complete sensor suite consisting of an accelerometer, an ADC for synchronous conversion of input from a third sensor, and a temperature sensor from Analog Devices. It measures both dynamic accelerations, resulting from motion or shock, and static acceleration, such as tilt, and allows selectable full-scale acceleration measurements in ranges of ±2g, ±4g, and ±8g (with a resolution of 1mg/LSB on the ±2g range). Acceleration is reported digitally, and the device communicates via the SPI protocol providing 12-bit output resolution for all three sensors.

The ADXL363 has two operating modes: Measurement mode for continuous, wide-bandwidth sensing; and Wake-up mode for limited bandwidth activity detection. Measurement mode represents its normal operating mode, and in this mode, acceleration data is read continuously, while the Wake-Up mode is ideal for simple detection of the presence or absence of motion at low power consumption. Wake-up mode helps implement a motion-activated ON/OFF switch, allowing the rest of the system to Power-Down until the activity is detected. In addition, measurement is suspended altogether by placing the device in Standby mode, reducing current consumption. During Standby, pending interrupts and data are preserved, and no new interrupts are generated.

In addition to a built-in accelerometer and temperature sensor, which the user can use to monitor internal system temperature or improve the device's temperature stability via calibration, the ADXL363 incorporates a 12-bit analog-to-digital converter (ADC) for digitization of external analog input. The ADC converts analog inputs ranging from 10% to 90% of the supply voltage and is best suited for use with a sensor input due to its synchronization with the accelerometer and temperature sensor.

The ADXL363 communicates with MCU through a standard SPI interface that enables clock speeds up to 8MHz, supporting the most common SPI mode - SPI Mode 0. This Click board™ also possesses two interrupt pins, INT1 and INT2, routed to the INT and PWM pins on the mikroBUS™, which above all have a dual function. First, they can be used as classic interrupt pins to signal MCU that an event has been sensed or can be used, e.g., INT1 as an input for external clocking and INT2 as input for synchronized sampling. One or both of these alternate functions can be used concurrently; however, if an interrupt pin is used for its alternate function, it cannot simultaneously be used for its primary function, to signal interrupts.

This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before use with 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.