30 min

Create a reliable tool to monitor, analyze, and manage currents using ACS70331 and STM32F767BI

Your pathway to exquisite current measurements

Hall Current 4 Click with Fusion for ARM v8

Published Aug 11, 2023

Click board™

Hall Current 4 Click

Development board

Fusion for ARM v8


NECTO Studio



Tap into efficient current use via our data-driven solution, leading to cost savings, productivity gains, and operational excellence



Hardware Overview

How does it work?

Hall Current 4 Click is based on the ACS70331, a current sensor from Allegro Microsystems, and the 12-bit ADC marked MCP3221, produced by Microchip. The ACS70331 uses GMR elements to indirectly measure the current flowing through the primary conductor of the IC by sensing the field produced by this current. This IC utilizes the field generated by the current passing through the primary conductor affects the voltage across the GMR sensor. The GMR sensor voltage changes even with a low field strength, which makes the ACS70331 very suitable for accurate

measurements of lower currents. However, the saturation happens quite soon after, making it unsuitable for higher currents. The ACS70331 has a sensitivity of 200 mV/A and can measure the current in the range from -5A to +5A. Considering that the operative range of the ACS70331 is approximately 1 MHz, the output voltage variations with the load current are quite fast with no latency. The output voltage from the ACS70331 is fed to the input of the analog-digital converter (ADC), which allows the reading of the conversion data via the I2C interface. The ACS70331 has a small primary

conductor resistance of 1.1 mΩ, resulting in low power dissipation and low-temperature rise due to current flow through the sensor. The sensor has no physical contact with the output pins on the chip as it operates exclusively by the principle of the field generated by the current, which runs through the input pins (primary conductor). The load voltage at the input pins is isolated from the rest of the chip. However, it is unsafe to use at voltages higher than 100V.

Hall Current 4 Click hardware overview image
Hall Current 4 Click Current Warning image

Features overview

Development board

Fusion for ARM 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 ARM® Cortex®-M based MCUs 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 ARM v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the Fusion for ARM 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 ARM 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 ARM v8 horizontal image

Microcontroller Overview

MCU Card / MCU



8th Generation


ARM Cortex-M7

MCU Memory (KB)


Silicon Vendor


Pin count


RAM (Bytes)


Used MCU Pins

mikroBUS™ mapper

Power Supply
I2C Clock
I2C Data
Power Supply

Take a closer look


Hall Current 4 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 ARM v8 as your development board.

Fusion for PIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
v8 SiBRAIN Access 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 Hall Current 4 Click driver.

Key functions:

  • hallcurrent4_get_current_data - This function reads current in mA

  • hallcurrent4_get_raw_data - This function reads raw (ADC) current data

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 HallCurrent4 Click example
 * # Description
 * Demo application shows is reading current data in mA using Hall current 4 click.
 * The demo application is composed of two sections :
 * ## Application Init 
 * Configuring clicks and log objects.
 * ## Application Task  
 * Reads Current value in mA and logs this data to USBUART every 1 sec.
 * \author Katarina Perendic
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "hallcurrent4.h"

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

static hallcurrent4_t hallcurrent4;
static log_t logger;

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

void application_init ( void )
    log_cfg_t log_cfg;
    hallcurrent4_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 ----" );

    //  Click initialization.

    hallcurrent4_cfg_setup( &cfg );
    hallcurrent4_init( &hallcurrent4, &cfg );

void application_task ( void )
    float current;

    current = hallcurrent4_get_current_data( &hallcurrent4 );

    log_printf( &logger, " >> Current value: %.2f mA\r\n", current );
    log_printf( &logger, " ------------------------- \r\n" );
    Delay_ms( 1000 );

void main ( void )
    application_init( );

    for ( ; ; )
        application_task( );

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

Additional Support