10 min

Achieve precise current monitoring in various industrial settings with HO 10-P and STM32F407VGT6

Current transducer with galvanic isolation and reliable measurements of DC, AC, and pulse currents up to 10ARMS

Current Sens 2 Click with Clicker 4 for STM32F4

Published Mar 19, 2024

Click board™

Current Sens 2 Click


Clicker 4 for STM32F4


NECTO Studio



Precise monitoring and control of both AC and DC currents, suitable for a wide range of applications where accurate current measurement and safety are crucial



Hardware Overview

How does it work?

Current Sens 2 Click is based on the HO 10-P, an AC/DC current transducer from LEM USA. The HO 10-P is well-known for measuring DC, AC, and pulse currents up to 10ARMS with galvanic isolation between the primary and secondary circuits. With its core built on the open-loop Hall effect measuring principle, the Current Sens 2 Click ensures precise and reliable current measurements. Its capability covers a variety of industrial applications, including AC variable speed drives, UPS systems, SMPS, and power supplies for welding, which benefit from low power consumption and high immunity to external interference. The device's fast response time suits dynamic and demanding environments. The HO 10-P is designed for through-hole PCB mounting and features a sizable aperture (8x8mm) for the primary

conductor, ensuring easy integration and versatility. Although the sensor can measure current up to 10A, its sensitivity can be altered in three specific scenarios. When current is applied to the input, for instance, pin 6, and the output is obtained from pin 11, the sensor's sensitivity becomes x1. This configuration is considered as the wire being wound only once around the sensor's core, marking the first scenario. In another configuration, short-circuiting pins 7 and 10 while keeping the input and output on pins 6 and 11 doubles the sensitivity (x2). Similarly, sensitivity triples (x3) when pins 7-10 and 8-9 are short-circuited, maintaining the input and output on pins 6 and 11. Maintaining a straight signal path from the input to the output is crucial, as depicted in the schematic (6-11, 7-10, 8-9). It's also possible to measure the conductor's current by

pulling it through the sensor's core and allowing current to flow through it. The sensor is powered by the 5V mikroBUS™ power rail and outputs the sensed current as an analog signal through the AN pin. Additionally, an orange LED and a dedicated pin (OCD) on the mikroBUS™ socket signal an overcurrent condition, providing enhanced safety and monitoring features. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

Current Sens 2 Click hardware overview image
Current Sens 2 Click Current Warning image

Features overview

Development board

Clicker 4 for STM32F4 is a compact development board designed as a complete solution that you can use to quickly build your own gadgets with unique functionalities. Featuring an STM32F407VGT6 MCU, four mikroBUS™ sockets for Click boards™ connectivity, power management, and more, it represents a perfect solution for the rapid development of many different types of applications. At its core is an STM32F407VGT6 MCU, a powerful microcontroller by STMicroelectronics based on the high-performance

Arm® Cortex®-M4 32-bit processor core operating at up to 168 MHz frequency. It provides sufficient processing power for the most demanding tasks, allowing Clicker 4 to adapt to any specific application requirements. Besides two 1x20 pin headers, four improved mikroBUS™ sockets represent the most distinctive connectivity feature, allowing access to a huge base of Click boards™, growing on a daily basis. Each section of Clicker 4 is clearly marked, offering an intuitive and clean interface. This makes working with the

development board much simpler and, thus, faster. The usability of Clicker 4 doesn’t end with its ability to accelerate the prototyping and application development stages: it is designed as a complete solution that can be implemented directly into any project, with no additional hardware modifications required. Four mounting holes [4.2mm/0.165”] at all four corners allow simple installation by using mounting screws.

Clicker 4 for STM32F4 double image

Microcontroller Overview

MCU Card / MCU



ARM Cortex-M4

MCU Memory (KB)


Silicon Vendor


Pin count


RAM (Bytes)


Used MCU Pins

mikroBUS™ mapper

Analog Output
Power Supply
Overcurrent Detection
Power Supply

Take a closer look


Current Sens 2 Click Schematic schematic

Step by step

Project assembly

Clicker 4 for STM32F4 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Clicker 4 for STM32F4 as your development board.

Clicker 4 for STM32F4 front image hardware assembly
LTE IoT 5 Click front image hardware assembly
LTE IoT 5 Click complete accessories setup image hardware assembly
Clicker 4 STM32F4 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 image step 5 hardware assembly
Necto image step 6 hardware assembly
Clicker 4 for STM32F4 HA MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.

Application Output Step 1

After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.

Application Output Step 3

Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.

Application Output Step 4

Software Support

Library Description

This library contains API for Current Sens 2 Click driver.

Key functions:

  • currentsens2_get_int_pin - Current Sens 2 get int pin state function

  • currentsens2_tare - Current Sens 2 tare function

  • currentsens2_get_current - Current Sens 2 read current function

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 Current Sens 2 Click Example.
 * # Description
 * This example demonstrates the use of Current Sens 2 click board by reading and
 * displaying the input current measurements.
 * The demo application is composed of two sections :
 * ## Application Init
 * Initializes the driver and logger.
 * ## Application Task
 * Reads the input current measurements and displays the results on the USB UART
 * approximately once per second.
 * @author Stefan Ilic

#include "board.h"
#include "log.h"
#include "currentsens2.h"

static currentsens2_t currentsens2;   /**< Current Sens 2 Click driver object. */
static log_t logger;    /**< Logger object. */

void application_init ( void )
    log_cfg_t log_cfg;  /**< Logger config object. */
    currentsens2_cfg_t currentsens2_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.
    currentsens2_cfg_setup( &currentsens2_cfg );
    CURRENTSENS2_MAP_MIKROBUS( currentsens2_cfg, MIKROBUS_1 );
    if ( ADC_ERROR == currentsens2_init( &currentsens2, &currentsens2_cfg ) )
        log_error( &logger, " Communication init." );
        for ( ; ; );
    log_printf( &logger, " Remove Click from the electrical circuit \r\n" );
    Delay_ms( 1000 );
    if ( CURRENTSENS2_ERROR == currentsens2_tare ( &currentsens2 ) )
        log_error( &logger, " Click tare error." );
        for ( ; ; );

    currentsens2_set_prim_turn_no( &currentsens2, CURRENTSENS2_NUM_OF_PASSES_1 );

    log_printf( &logger, " Connect Click to the electrical circuit \r\n" );
    log_info( &logger, " Application Task " );

void application_task ( void ) 
    float current = 0;
    if ( CURRENTSENS2_OK == currentsens2_get_current ( &currentsens2, &current ) ) 
        log_printf( &logger, " Current : %.2f[A]\r\n\n", current );
        Delay_ms( 1000 );

void main ( void ) 
    application_init( );

    for ( ; ; ) 
        application_task( );

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

Additional Support