30 min

Measure a wide range of current values using CT415 and STM32F334R8

Currently the best!

Current 9 Click with UNI Clicker

Published Mar 06, 2023

Click board™

Current 9 Click

Development board

UNI Clicker


NECTO Studio



Precise and accurate current sensing solution



Hardware Overview

How does it work?

Current 9 Click is based on the CT415-HSN830DR, an XtremeSense® TMR current sensor providing high-accuracy current measurements from Crocus Technology. The CT415-HSN830DR has an integrated current-carrying conductor (CCC) that handles the current from 0A up to 30A. It has high sensitivity and a wide dynamic range with excellent accuracy (low total output error), making it suitable for many consumer, enterprise, and industrial applications. When current flows through the CCC, the XtremeSense® TMR sensors inside the chip sense the field, generating a differential voltage signal that goes through the analog front-end to output a current measurement with less than ±1% full-scale total output error. The CT415-HSN830DR

is designed to enable a fast response time for the current measurement. In addition, the user can select the output voltage level of the sensor performed by the onboard SMD jumper by populating it to an appropriate position marked as 3V3 or 5V. Even with high bandwidth of 1MHz, the CT415-HSN830DR consumes minimal power. The output signal of the CT415-HSN830DR can be converted to a digital value using MCP3221, a successive approximation A/D converter with a 12-bit resolution from Microchip using a 2-wire I2C compatible interface, or can be sent directly to an analog pin of the mikroBUS™ socket labeled as AN. The selection can be made by an onboard SMD jumper labeled ADC SEL, placing it in an

appropriate position marked as EXT and INT. Also, this Click board™ should be connected in series with the load. Two onboard terminal connectors measure the current, one terminal block for the positive and the other for the negative current input. 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. However, the 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 9 Click Current Warning image

Features overview

Development board

UNI Clicker is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It supports a wide range of microcontrollers, such as different ARM, PIC32, dsPIC, PIC, and AVR from various vendors like Microchip, ST, NXP, and TI (regardless of their number of pins), four mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a debugger/programmer connector, and two 26-pin headers for interfacing with external electronics. Thanks to innovative manufacturing technology, it allows you to build

gadgets with unique functionalities and features quickly. Each part of the UNI Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the UNI Clicker programming method, using a third-party programmer or CODEGRIP/mikroProg connected to onboard JTAG/SWD header, the UNI Clicker board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Type-C (USB-C) connector, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or using a Li-Po/Li

Ion battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board (plus USB HOST/DEVICE), including the well-established mikroBUS™ socket, a standardized socket for the MCU card (SiBRAIN standard), and several user-configurable buttons and LED indicators. UNI Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

UNI clicker double 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

Analog Signal
Power Supply
I2C Clock
I2C Data
Power Supply

Take a closer look


Current 9 Click Schematic schematic

Step by step

Project assembly

UNI Clicker front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI Clicker as your development board.

UNI Clicker front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for STM32F745VG front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
UNI Clicker 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
Necto image step 7 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 9 Click driver.

Key functions:

  • current9_read_voltage This function reads the raw ADC value and converts it to a proportional voltage level.

  • current9_read_current This function reads the input current level [A] based on @b CURRENT9_NUM_CONVERSIONS of voltage measurements.

  • current9_set_vref This function sets the voltage reference for the Current 9 Click driver.

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 9 Click Example.
 * # Description
 * This example demonstrates the use of Current 9 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.
 * @note
 * For better accuracy, set the voltage reference by using the @b current9_set_vref function,
 * increase the number of conversions by modifying the @b CURRENT9_NUM_CONVERSIONS macro, 
 * and adjust the @b CURRENT9_ZERO_CURRENT_OFFSET voltage value.
 * @author Stefan Filipovic

#include "board.h"
#include "log.h"
#include "current9.h"

static current9_t current9;   /**< Current 9 Click driver object. */
static log_t logger;    /**< Logger object. */

void application_init ( void )
    log_cfg_t log_cfg;  /**< Logger config object. */
    current9_cfg_t current9_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.
    current9_cfg_setup( &current9_cfg );
    CURRENT9_MAP_MIKROBUS( current9_cfg, MIKROBUS_1 );
    err_t init_flag = current9_init( &current9, &current9_cfg );
    if ( ( ADC_ERROR == init_flag ) || ( I2C_MASTER_ERROR == init_flag ) )
        log_error( &logger, " Communication init." );
        for ( ; ; );
    log_info( &logger, " Application Task " );

void application_task ( void ) 
    float current = 0;
    if ( CURRENT9_OK == current9_read_current ( &current9, &current ) ) 
        log_printf( &logger, " Current : %.3f[A]\r\n\n", current );
        Delay_ms( 1000 );

void main ( void ) 
    application_init( );

    for ( ; ; ) 
        application_task( );

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

Additional Support