30 min

Measure acceleration in three axis with MXC6655XA and STM32L432KC

Object's inclination and vibration

Accel 24 Click with Fusion for STM32 v8

Published Mar 03, 2023

Click board™

Accel 24 Click

Development board

Fusion for STM32 v8


NECTO Studio



Precise measurements of vibration or shock for a variety of applications



Hardware Overview

How does it work?

Accel 24 Click is based on the MXC6655XA, a highly reliable digital triaxial acceleration from MEMSIC. The MXC6655XA is highly configurable with a programmable acceleration range of ±2g, ±4g, or ±8g based on MEMSIC's proprietary thermal technology built with a 0.18μm standard CMOS process. It contains no moving sensor parts, eliminating field reliability and repeatability issues; no measurable resonance (immunity to vibration), stiction, or detectable hysteresis exists. The MXC6655XA also eliminates the "click" sounds typically heard in ball-based orientation sensors. The MEMS structure

is greater than 200,000g. This sensor provides X/Y/Z axis acceleration signals with a low 0g offset and temperature signals with high accuracy. In addition, it also detects six orientation positions, X/Y shake, and shakes directions. Accel 24 Click communicates with an MCU using the standard I2C 2-Wire interface to read data and configure settings capable of operating in a standard or fast mode of operation. The acceleration signal is provided in 12-bit output resolution. In addition to communication pins, this board also possesses an additional interrupt pin routed to the INT pin

on the mikroBUS™ socket, for orientation and X/Y shake detections. The MXC6655XA allows users to be placed in a Power-Down mode enabled through the I2C interface. This 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.

Accel 24 Click top side image
Accel 24 Click lateral side image
Accel 24 Click bottom side image

Features overview

Development board

Fusion for STM32 v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different 32-bit ARM® Cortex®-M based MCUs from STMicroelectronics, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, Fusion for STM32 v8 provides a fluid and immersive working experience, allowing

access anywhere and under any circumstances at any time. Each part of the Fusion for STM32 v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.

Communication options such as USB-UART, USB HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. Fusion for STM32 v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

Fusion for STM32 v8 horizontal image

Microcontroller Overview

MCU Card / MCU



8th Generation


ARM Cortex-M4

MCU Memory (KB)


Silicon Vendor


Pin count


RAM (Bytes)


Used MCU Pins

mikroBUS™ mapper

Power Supply
I2C Clock
I2C Data

Take a closer look


Accel 24 Click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Fusion for STM32 v8 as your development board.

Fusion for PIC v8 front image hardware assembly
Buck 22 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
v8 SiBRAIN MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART Application Output Step 4

Software Support

Library Description

This library contains API for Accel 24 Click driver.

Key functions:

  • accel24_get_int_pin This function returns the INT pin logic state.

  • accel24_read_data This function checks the data ready bit, clears it, and then reads the accel (X, Y, Z) and temperature measurements.

  • accel24_set_full_scale_range This function sets the full-scale range resolution.

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

 * @file main.c
 * @brief Accel 24 Click example
 * # Description
 * This example demonstrates the use of Accel 24 click board by reading and displaying 
 * accel data (X, Y, and Z axis) as well as temperature measurements on the USB UART.
 * The demo application is composed of two sections :
 * ## Application Init
 * Initializes the driver and performs the click default configuration.
 * ## Application Task
 * Reads and displays the accel data (X, Y, and Z axis) as well as temperature measurements
 * on the USB UART every 100ms approximately.
 * @author Stefan Filipovic

#include "board.h"
#include "log.h"
#include "accel24.h"

static accel24_t accel24;
static log_t logger;

void application_init ( void ) 
    log_cfg_t log_cfg;  /**< Logger config object. */
    accel24_cfg_t accel24_cfg;  /**< Click config object. */

     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, " Application Init " );

    // Click initialization.
    accel24_cfg_setup( &accel24_cfg );
    ACCEL24_MAP_MIKROBUS( accel24_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == accel24_init( &accel24, &accel24_cfg ) ) 
        log_error( &logger, " Communication init." );
        for ( ; ; );
    if ( ACCEL24_ERROR == accel24_default_cfg ( &accel24 ) )
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    log_info( &logger, " Application Task " );

void application_task ( void ) 
    accel24_data_t meas_data;
    // Wait for data ready indication
    while ( accel24_get_int_pin ( &accel24 ) );
    if ( ACCEL24_OK == accel24_read_data ( &accel24, &meas_data ) )
        log_printf( &logger, " X: %.3f g\r\n", meas_data.x );
        log_printf( &logger, " Y: %.3f g\r\n", meas_data.y );
        log_printf( &logger, " Z: %.3f g\r\n", meas_data.z );
        log_printf( &logger, " Temperature: %.2f degC\r\n", meas_data.temperature );
    Delay_ms ( 100 );

void main ( void ) 
    application_init( );

    for ( ; ; ) 
        application_task( );

// ------------------------------------------------------------------------ END

Additional Support