Measure current flow without direct contact with the conductor with BM14270 and STM32C031C6

Current sensing solution based on a magnetic MI (Magnetic Impedance) sensor

Current 14 Click with Nucleo 64 with STM32C031C6 MCU

Published Nov 19, 2024

Click board™

Current 14 Click

Dev. board

Nucleo 64 with STM32C031C6 MCU

Compiler

NECTO Studio

MCU

STM32C031C6

Monitor current consumption in industrial machines and equipment

Hardware Overview

How does it work?

Current 14 Click is based on the BM14270 (BM14270AMUV-LB), a magnetic current sensor IC from ROHM Semiconductor. Engineered for long-term support in the industrial market, this coreless, non-contact current sensing solution uses a magnetic MI (Magnetic Impedance) sensor, enabling accurate current measurement with minimal power loss. Its non-invasive design allows it to measure current flowing through a conductor without direct contact, making it both efficient and adaptable for various applications. This Click board™ is an ideal solution for scenarios requiring accurate current monitoring without introducing additional load or loss into the circuit, providing robust support in demanding environments. Current 14 Click uses a standard 2-wire I2C communication

protocol to enable the host MCU to control the TSC1641. The I2C interface supports clock frequencies up to 400kHz, with the I2C address selectable via the ADDR SEL jumper. Data output is provided through a 14-bit digital format via the I2C interface, delivering high precision in current detection. The sensor’s magnetic measurable range extends to ±280μT (typical), with a magnetic sensitivity of 0.045μT/LSB, allowing for fine-tuned and reliable measurements across various applications. This capability particularly benefits industrial equipment monitoring, power measurement meters, uninterruptible power supplies (UPS), and power conditioning systems. This Click board™ also includes an alert interrupt pin, ALR, as a data-ready indicator. In addition to

the standard interface pins, the ALR pin signals when new measurement data is available, streamlining the data acquisition process and ensuring timely updates for the host MCU. This feature enhances the board’s responsiveness in real-time monitoring applications, making it particularly effective for dynamic systems where precise and immediate current data is essential. 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 14 Click hardware overview image

Features overview

Development board

Nucleo-64 with STM32C031C6 MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin

headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is

provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.

Nucleo 64 with STM32C031C6 MCU double side image

Microcontroller Overview

MCU Card / MCU

Architecture

ARM Cortex-M0

MCU Memory (KB)

Silicon Vendor

STMicroelectronics

Pin count

RAM (Bytes)

12K

You complete me!

Accessories

Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.

Used MCU Pins

mikroBUS™ mapper

RST

ID COMM

PB12

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM

Alarm Interrupt

PC14

INT

I2C Clock

PB8

SCL

I2C Data

PB9

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

Click Shield for Nucleo-64 accessories 1 image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo 64 with STM32C031C6 MCU as your development board.

Nucleo 64 with STM32F401RE MCU front image hardware assembly

LTE IoT 5 Click front image hardware assembly

LTE IoT 5 Click complete accessories setup image hardware assembly

Board mapper by product8 hardware assembly

Clicker 4 for STM32F4 HA MCU Step hardware assembly

Necto No Display image step 8 hardware assembly

Debug Image Necto Step hardware assembly

Software Support

Library Description

This library contains API for Current 14 Click driver.

Key functions:

current14_calib_offset - This function calibrates the zero current offset value.
current14_calib_resolution - This function calibrates the data resolution at the known load current.
current14_get_current - This function reads the input current level [A].

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 14 Click example
 *
 * # Description
 * This example demonstrates the use of Current 11 Click board by reading and
 * displaying the input current measurements.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and calibrates the zero current offset and data resolution
 * at 3A load current.
 *
 * ## Application Task
 * Reads the input current measurements and displays the results on the USB UART
 * approximately once per second.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "current14.h"

static current14_t current14;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    current14_cfg_t current14_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.
    current14_cfg_setup( &current14_cfg );
    CURRENT14_MAP_MIKROBUS( current14_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == current14_init( &current14, &current14_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( CURRENT14_ERROR == current14_default_cfg ( &current14 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }

    log_printf( &logger, " Calibrating zero current offset in 5 seconds...\r\n" );
    log_printf( &logger, " Make sure no current flows through the sensor during the calibration process.\r\n" );
    for ( uint8_t cnt = 5; cnt > 0; cnt-- )
    {
        log_printf( &logger, " %u\r\n", ( uint16_t ) cnt );
        Delay_ms ( 1000 );
    }
    if ( CURRENT14_ERROR == current14_calib_offset ( &current14 ) )
    {
        log_error( &logger, " Calibrate offset." );
        for ( ; ; );
    }
    log_printf( &logger, " Offset calibration DONE.\r\n\n" );

    log_printf( &logger, " Calibrating data resolution in 5 seconds...\r\n" );
    log_printf( &logger, " Keep the load current set at 3A during the calibration process.\r\n" );
    for ( uint8_t cnt = 5; cnt > 0; cnt-- )
    {
        log_printf( &logger, " %u\r\n", ( uint16_t ) cnt );
        Delay_ms ( 1000 );
    }
    if ( CURRENT14_ERROR == current14_calib_resolution ( &current14, 3.0f ) )
    {
        log_error( &logger, " Calibrate resolution." );
        for ( ; ; );
    }
    log_printf( &logger, " Data resolution calibration DONE.\r\n" );
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    float current = 0;
    if ( CURRENT14_OK == current14_get_current ( &current14, &current ) )
    {
        log_printf ( &logger, " Current: %.3f A\r\n\n", current );
    }
}

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