10 min

Provide precise information about the object's speed or direction of movement using H3LIS331DL and STM32F042C6

Accelerometers: The unsung heroes of the tech world

Accel 3 Click with Fusion for STM32 v8

Published Oct 05, 2023

Click board™

Accel 3 Click

Development board

Fusion for STM32 v8


NECTO Studio



Accelerometers are fundamental sensors utilized across industries to measure and record changes in velocity or direction, enabling precise motion analysis and control



Hardware Overview

How does it work?

Accel 3 Click is based on the H3LIS331DL, a low-power, high-g 3-axis digital accelerometer from STMicroelectronics. The proprietary process technology allows the processing of suspended silicon structures, which are attached to the substrate in a few points called anchors, free to move in the direction of the sensed acceleration. When acceleration is applied to the sensor, the proof mass displaces from its nominal position, causing an imbalance in the capacitive half bridge. This imbalance is measured using charge integration in response to a voltage pulse applied to the capacitor. The sensor interface is factory-calibrated for sensitivity and zero-g level. The trim values are stored inside the device in non-volatile memory. Any time the device is turned on,

the trim parameters are downloaded into the registers to be used during active operation, allowing the device to be used without further calibration. The acceleration data of Accel 3 Click is accessed through an I2C or SPI interface, with a 400KHz fast mode frequency for I2C and a 10MHz clock frequency for SPI communication. The selection is made by positioning four SMD jumpers labeled SPI I2C in an appropriate position, with the I2C set by default. 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 H3LIS331DL allows choosing the least significant bit (LSB) of its I2C slave address using the SMD jumper labeled I2C ADDR (0 set by default). The H3LIS331DL

also possesses two inertial interrupts, both accessible over the INT2 INT1 jumper and INT pin of the mikroBUS™ socket. The user can completely program the functions, threshold, and timing of the two interrupt signals through the selected interface. They signal the host MCU that a motion event has been sensed. 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.

Accel 3 Click top side image
Accel 3 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-M0

MCU Memory (KB)


Silicon Vendor


Pin count


RAM (Bytes)


Used MCU Pins

mikroBUS™ mapper

SPI Chip Select
SPI Clock
Power Supply
I2C Clock
I2C Data

Take a closer look


Accel 3 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 3 Click driver.

Key functions:

  • accel3_default_cfg - This function select communication mode and executes start initialization

  • accel3_read_data - This function reads Accel data ( X, Y and Z axis ) from the desired Accel registers of the H3LIS331DL module

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 
 * \brief Accel3 Click example
 * # Description
 * Accel 3 Click represent 3-axis linear accelerometer.
 * The demo application is composed of two sections :
 * ## Application Init 
 * Application Init performs Logger and Click initialization.
 * ## Application Task  
 * This is an example which demonstrates the usage of Accel 3 Click board.
 * Measured coordinates (X,Y,Z) are being sent to the UART where you can 
 * track their changes. All data logs on USB UART for every 1 sec.
 * \author Mihajlo Djordjevic
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "accel3.h"

// ------------------------------------------------------------------ VARIABLES

static accel3_t accel3;
static log_t logger;

accel3_data_t accel3_data;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
    log_cfg_t log_cfg;
    accel3_cfg_t cfg;

     * 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 ----" );
    Delay_ms ( 100 );

    //  Click initialization.

    accel3_cfg_setup( &cfg );
    accel3_init( &accel3, &cfg );
    log_printf( &logger, "--------------------------\r\n\n" );
    log_printf( &logger, " -----  Accel 3 Click  -----\r\n" );
    log_printf( &logger, "--------------------------\r\n\n" );
    Delay_ms ( 1000 );
    accel3_default_cfg ( &accel3, &cfg );
    Delay_ms ( 100 );
    log_printf( &logger, " -- Initialization  done. --\r\n" );
    log_printf( &logger, "--------------------------\r\n\n" );
    Delay_ms ( 1000 );

void application_task ( void )
    accel3_read_data( &accel3, &accel3_data );
    Delay_ms ( 100 );
    log_printf( &logger, "        Accelerometer       \r\n" );
    log_printf( &logger, "----------------------------\r\n" );
    log_printf( &logger, "        X = %d \r\n", accel3_data.x );
    log_printf( &logger, "        Y = %d \r\n", accel3_data.y );
    log_printf( &logger, "        Z = %d \r\n", accel3_data.z );
    log_printf( &logger, "----------------------------\r\n" );
    Delay_ms ( 1000 );

void main ( void )
    application_init( );

    for ( ; ; )
        application_task( );

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

Additional Support