Beginner
10 min

Measure current flow without direct contact with the conductor with BM14270 and PIC32MZ2048EFM100

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

Current 14 Click with Curiosity PIC32 MZ EF

Published Nov 19, 2024

Click board™

Current 14 Click

Dev. board

Curiosity PIC32 MZ EF

Compiler

NECTO Studio

MCU

PIC32MZ2048EFM100

Monitor current consumption in industrial machines and equipment

A

A

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

Curiosity PIC32 MZ EF development board is a fully integrated 32-bit development platform featuring the high-performance PIC32MZ EF Series (PIC32MZ2048EFM) that has a 2MB Flash, 512KB RAM, integrated FPU, Crypto accelerator, and excellent connectivity options. It includes an integrated programmer and debugger, requiring no additional hardware. Users can expand

functionality through MIKROE mikroBUS™ Click™ adapter boards, add Ethernet connectivity with the Microchip PHY daughter board, add WiFi connectivity capability using the Microchip expansions boards, and add audio input and output capability with Microchip audio daughter boards. These boards are fully integrated into PIC32’s powerful software framework, MPLAB Harmony,

which provides a flexible and modular interface to application development a rich set of inter-operable software stacks (TCP-IP, USB), and easy-to-use features. The Curiosity PIC32 MZ EF development board offers expansion capabilities making it an excellent choice for a rapid prototyping board in Connectivity, IOT, and general-purpose applications.

Curiosity PIC32MZ EF double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
ID COMM
RPD4
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Alarm Interrupt
RF13
INT
NC
NC
TX
NC
NC
RX
I2C Clock
RPA14
SCL
I2C Data
RPA15
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

Current 14 Click Schematic schematic

Step by step

Project assembly

Curiosity PIC32MZ EF front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity PIC32 MZ EF as your development board.

Curiosity PIC32MZ EF front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
Board mapper by product7 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
Curiosity PIC32 MZ EF 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

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 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

Additional Support

Resources

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