Accel&Pressure Click

How does it work?

Accel&Pressure Click is based on the FXLS8974CF, a 3-axis low-g accelerometer, and the MPL3115A2, a precision pressure sensor with altimetry, both from NXP Semiconductor. The accelerometer has a ±2/4/8/16 g user-selectable, full-scale measurement range with a 12-bit acceleration data output. It can work in several modes, such as active, hibernate, standby, and more. The integrated FIFO/LIFO buffer of 144 bytes can store 32 12-bit X/Y/Z/ data triplets. The sensor also has flexible data change detection, such as motion, freefall, and other inertial events. The pressure sensor has an absolute operating range of 20kPa to 110kPa in 20-bit measurements. Besides the pressure, the MPL3115A2 can also measure the altitude in a range of -698 up to 11775 meters in a 20-bit resolution. It also comes with an embedded FIFO (32 samples) and up to 12 days of data logging using the FIFO. Both sensors have an integrated temperature sensor and are temperature-compensated.

Accel&Pressure Click uses a standard 2-wire I2C interface to allow the host MCU to communicate with both sensors. If the motion is detected, the FXLS8974CF uses a motion MOT pin to interrupt the host MCU. Depending on your application, you can choose one of the available pins (PWM, AN, CS) by soldering one of the jumpers (R8, R9, R10) to control the hibernation mode wake-up function of the FXLS8974CF. In addition, there are LP Cut jumpers at the bottom of the Accel&Pressure Click board™, with which a low power consumption feature can be achieved.

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. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Specifications

Pinout diagram

This table shows how the pinout on Accel&Pressure Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Hibernation Mode Wake-Up	AN	1	AN	PWM	16	PWM	Hibernation Mode Wake-Up
ID SEL	RST	2	RST	INT	15	MOT	Motion Detection
Hibernation Mode Wake-Up / ID COMM	CS	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C Clock
	NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Accel&Pressure Click electrical specifications

Software Support

We provide a library for the AccelPressure Click as well as a demo application (example), developed using MIKROE compilers. The demo can run on all the main MIKROE development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for AccelPressure Click driver.

Key functions

• accelpressure_get_axes_data This function reads the accelerometer sensor axes data.

• accelpressure_get_pressure This function reads the sensor pressure data conversion in mbar.

• accelpressure_get_temperature This function reads the conversion of sensor pressure data in degrees Celsius.

Example Description

This library contains API for the AccelPressure Click driver. The library initializes and defines the I2C drivers to write and read data from registers, as well as the default configuration for the reading accelerator, pressure, and temperature data.

void application_task ( void )  
 { 
     accelpressure_axes_t acc_axis; 
     float pressure = 0, temperature = 0; 
     if ( ACCELPRESSURE_OK == accelpressure_get_axes_data( &accelpressure, &acc_axis ) ) 
     { 
         log_printf( &logger, " Accel X: %.2f mgrn", acc_axis.x ); 
         log_printf( &logger, " Accel Y: %.2f mgrn", acc_axis.y ); 
         log_printf( &logger, " Accel Z: %.2f mgrn", acc_axis.z ); 
     } 
     log_printf( &logger, "_________________rn" ); 
     Delay_ms( 100 ); 

     if ( ACCELPRESSURE_OK == accelpressure_get_pressure( &accelpressure, &pressure ) ) 
     { 
         log_printf( &logger, " Pressure: %.2f mbarrn", pressure ); 
     } 
     Delay_ms( 100 ); 

     if ( ACCELPRESSURE_OK == accelpressure_get_temperature( &accelpressure, &temperature ) ) 
     { 
         log_printf( &logger, " Temperature: %.2f mbarrn", temperature ); 
     } 
     log_printf( &logger, "_________________rn" ); 
     Delay_ms( 1000 ); 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.AccelPressure

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK - MIKROE Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.