Achieve operational excellence by utilizing our current measurement solution to track current variations, enabling you to make data-driven decisions for improved efficiency and reduced downtime
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Hardware Overview
How does it work?
Current 4 Click is based on the INA250, a current-sense amplifier with a high-precision, low-drift shunt resistor, which can deliver highly accurate measurements over a wide temperature range from Texas Instruments. The INA250 measures the voltage developed across the internal current-sensing resistor when current passes through it. The integrated 2mΩ shunt resistor offers 0.1% tolerance and a low drift of 15pmm/°C, enabling the higher performance of the end equipment. This amplifier allows for high-accuracy current measurements at common-mode voltages and offers a maximum error of 0.84% over a wide temperature range. Current 4 Click communicates with MCU using only one pin routed on the AN pin of the mikroBUS™ socket. The output analog
signal from INA250 is forwarded to the input of the operational amplifier, the LMV321 low-voltage rail-to-rail OpAmp from Texas Instruments, representing the most cost-effective solution for applications where low voltage operation is needed. The output of the LMV321 OpAmp has a stable unity gain, acting as a buffer so that the host MCU can sample the output voltage of the INA250 via the AN pin of the mikroBUS™ socket. The INA250 can be configured to measure both unidirectional and bidirectional currents through the reference voltage level. For unidirectional operation, the reference pin should be tied to the ground. When the current increases, the output signal increases upwards from this reference voltage (or ground in this case). For bidirectional
currents, an external voltage source can be used as the reference voltage; in this case, a low dropout linear regulator AP7331 from Diodes Incorporated provides the 2.5V reference supply voltage for the INA250. The reference voltage level can be selected by positioning the SMD jumper labeled VREF SEL to an appropriate position choosing between 2.5V provided by AP7331 or GND. 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.

Features overview
Development board
Nucleo 32 with STM32F031K6 MCU board provides an affordable and flexible platform for experimenting with STM32 microcontrollers in 32-pin packages. Featuring Arduino™ Nano connectivity, it allows easy expansion with specialized shields, while being mbed-enabled for seamless integration with online resources. The
board includes an on-board ST-LINK/V2-1 debugger/programmer, supporting USB reenumeration with three interfaces: Virtual Com port, mass storage, and debug port. It offers a flexible power supply through either USB VBUS or an external source. Additionally, it includes three LEDs (LD1 for USB communication, LD2 for power,
and LD3 as a user LED) and a reset push button. The STM32 Nucleo-32 board is supported by various Integrated Development Environments (IDEs) such as IAR™, Keil®, and GCC-based IDEs like AC6 SW4STM32, making it a versatile tool for developers.
Microcontroller Overview
MCU Card / MCU

Architecture
ARM Cortex-M0
MCU Memory (KB)
32
Silicon Vendor
STMicroelectronics
Pin count
32
RAM (Bytes)
4096
You complete me!
Accessories
Click Shield for Nucleo-32 is the perfect way to expand your development board's functionalities with STM32 Nucleo-32 pinout. The Click Shield for Nucleo-32 provides two mikroBUS™ sockets to add any functionality from our ever-growing range of Click boards™. We are fully stocked with everything, from sensors and WiFi transceivers to motor control and audio amplifiers. The Click Shield for Nucleo-32 is compatible with the STM32 Nucleo-32 board, providing an affordable and flexible way for users to try out new ideas and quickly create prototypes with any STM32 microcontrollers, choosing from the various combinations of performance, power consumption, and features. The STM32 Nucleo-32 boards do not require any separate probe as they integrate the ST-LINK/V2-1 debugger/programmer and come with the STM32 comprehensive software HAL library and various packaged software examples. This development platform provides users with an effortless and common way to combine the STM32 Nucleo-32 footprint compatible board with their favorite Click boards™ in their upcoming projects.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic

Step by step
Project assembly
Track your results in real time
Application Output
1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.

2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.

3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.

Software Support
Library Description
This library contains API for Current 4 Click driver.
Key functions:
current4_read_load_current
- Read load currentcurrent4_read_an_pin_voltage
- Read AN pin voltage level functioncurrent4_read_an_pin_value
- Read AN pin value function.
Open Source
Code example
The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.
/*!
* @file main.c
* @brief Current 4 Click Example.
*
* # Description
* This example showcases the ability of the Current 4 Click board.
* It configures Host MCU for communication and reads the voltage
* of AN pin and calculates current on load output.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization of the communication modules(ADC and UART).
*
* ## Application Task
* In span on 500ms reads voltage and calculates the current on load.
*
* @author Luka Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "current4.h"
static current4_t current4; /**< Current 4 Click driver object. */
static log_t logger; /**< Logger object. */
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
current4_cfg_t current4_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.
current4_cfg_setup( ¤t4_cfg );
CURRENT4_MAP_MIKROBUS( current4_cfg, MIKROBUS_1 );
if ( ADC_ERROR == current4_init( ¤t4, ¤t4_cfg ) )
{
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float current4_load_current = 0;
if ( ADC_ERROR != current4_read_load_current ( ¤t4, ¤t4_load_current ) )
{
log_printf( &logger, " > Load current : %.2f[A]\r\n", current4_load_current );
log_printf( &logger, "**********************\r\n" );
}
Delay_ms ( 500 );
}
int main ( void )
{
/* Do not remove this line or clock might not be set correctly. */
#ifdef PREINIT_SUPPORTED
preinit();
#endif
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
/*!
* @file main.c
* @brief Current 4 Click Example.
*
* # Description
* This example showcases the ability of the Current 4 Click board.
* It configures Host MCU for communication and reads the voltage
* of AN pin and calculates current on load output.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization of the communication modules(ADC and UART).
*
* ## Application Task
* In span on 500ms reads voltage and calculates the current on load.
*
* @author Luka Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "current4.h"
static current4_t current4; /**< Current 4 Click driver object. */
static log_t logger; /**< Logger object. */
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
current4_cfg_t current4_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.
current4_cfg_setup( ¤t4_cfg );
CURRENT4_MAP_MIKROBUS( current4_cfg, MIKROBUS_1 );
if ( ADC_ERROR == current4_init( ¤t4, ¤t4_cfg ) )
{
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float current4_load_current = 0;
if ( ADC_ERROR != current4_read_load_current ( ¤t4, ¤t4_load_current ) )
{
log_printf( &logger, " > Load current : %.2f[A]\r\n", current4_load_current );
log_printf( &logger, "**********************\r\n" );
}
Delay_ms ( 500 );
}
int main ( void )
{
/* Do not remove this line or clock might not be set correctly. */
#ifdef PREINIT_SUPPORTED
preinit();
#endif
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END