Transform current measurements into actionable intelligence using MLX91210 and TM4C129ENCPDT

Where current measurement meets sublime precision!

Hall Current 3 click with Fusion for Tiva v8

Published Aug 10, 2023

Click board™

Hall Current 3 click

Dev. board

Fusion for Tiva v8

Compiler

NECTO Studio

MCU

TM4C129ENCPDT

Enhance safety protocols and system integrity by leveraging our solution's accurate current measurements to detect irregularities and potential risks

Hardware Overview

How does it work?

Hall Current 3 Click is based on the MLX91210, a linear Hall current sensor from Melexis. This sensor utilizes the Hall effect phenomenon to measure the current passing through the input pins of the IC. This allows the series resistance to stay very low, in magnitudes of μΩ, reducing dissipation and losses in the main current flow. The main current flow through the input rails of the IC generates a magnetic field, which causes the Hall effect on two integrated Hall plates. These two plates are connected differentially, preventing foreign magnetic interferences from influencing the measurement. A front-end section conditions and amplifies the signal, canceling out interferences. The conditioned signal is then available at the VOUT pin of the MLX91210, with a linear dependency on the input current. It is further routed to an A/D converter. The VOUT voltage is stable and has a low sensitivity drift over temperature (±1.5 % with nominal current). The VOUT pin of the

MLX91210 stays at 50% of VDD (5V) at 0A of current. This allows you to measure both polarities: positive current polarity will pull the VOUT above half of the VDD, while negative current polarity will draw the VOUT pin below the VDD voltage. The MLX91210 also features fault reporting if overvoltage, undervoltage, or calibration data CRC error occurs. It will set the VOUT pin to a high impedance mode (Hi-Z). The datasheet offers an explanation about Hi-Z timings for each type of error. The resolution of the MLX91210 IC can be determined from the full IC label: MLX91210KDF-CAS-101-SP, where CAS-101 means that it has the analog voltage resolution of 80mV/A or ±25A for the full scale (FS) measurement. The output voltage is also routed to the MCP3221, a 12 Bit SAR type ADC with the I2C interface, from Microchip. This ADC is used in several different Click board™ designs, as it yields accurate conversions, requires a low count of external components, and has a

reasonably good signal-to-noise ratio (SNR). It can achieve up to 22.3ksps, which allows good measurement resolution for most purposes. After the VOUT measurement voltage has been converted to a digital value, it can be read via the I2C bus of the MCP3221 ADC. Since the ADC IC works only with 3.3V communication voltage levels, the Click board™ is equipped with the PCA9306, a bi-directional I2C level translator. This IC accepts two voltage levels: one for the input signal and another for the output signal. The VCC SEL jumper can select the output reference signal, allowing communication with both 3.3V and 5V MCUs. The I2C bus already includes pull-up resistors, so no further configuration is needed; it can be used immediately. The input terminal has a cross-section of 2.5mm so that it can accept a high input current of more than 10A. It has two input poles: IP+ and IP-. Conductors with the current that needs to be measured can be connected to this terminal.

Hall Current 3 click hardware overview image

Hall Current 3 Click Current Warning image

Features overview

Development board

Fusion for TIVA v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different 32-bit ARM® Cortex®-M based MCUs from Texas Instruments, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over a WiFi network. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, Fusion for TIVA v8 provides a fluid and immersive working experience, allowing access

anywhere and under any circumstances at any time. Each part of the Fusion for TIVA v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.

Communication options such as USB-UART, USB HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. Fusion for TIVA v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

Microcontroller Overview

MCU Card / MCU

Type

8th Generation

Architecture

ARM Cortex-M4

MCU Memory (KB)

1024

Silicon Vendor

Texas Instruments

Pin count

128

RAM (Bytes)

262144

Used MCU Pins

mikroBUS™ mapper

RST

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM

INT

I2C Clock

PD2

SCL

I2C Data

PD3

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Hall Current 3 click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Fusion for Tiva v8 as your development board.

NECTO Output Selection Step Image hardware assembly

In the advanced settings, pay special attention to the Redirect standard output field. By default, it is set to Application output as the method of displaying final results. To show results via a UART terminal, select the “UART” option in that field and click the “SAVE” button. You will be returned to the Compiler field, and now you can move on to the next step by pressing the “NEXT” button.

GNSS2 Click front image hardware assembly

SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly

GNSS2 Click complete accessories setup image hardware assembly

Board mapper by product7 hardware assembly

NECTO Compiler Selection Step Image hardware assembly

Software Support

Library Description

This library contains API for Hall Current 3 Click driver.

Key functions:

hallcurrent3_getCurrent - This function calculates the current value
hallcurrent3_read_data - This function read two bytes of data from the specified register

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 
 * \brief HallCurrent3 Click example
 * 
 * # Description
 * The example starts off with the logger and Click modules and then starts measuring and
 * displaying current values.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes and configures the logger and Click modules.
 * 
 * ## Application Task  
 * Reads and displays current values every second.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "hallcurrent3.h"

// ------------------------------------------------------------------ VARIABLES

static hallcurrent3_t hallcurrent3;
static log_t logger;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( )
{
    log_cfg_t log_cfg;
    hallcurrent3_cfg_t cfg;

    /** 
     * 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.

    hallcurrent3_cfg_setup( &cfg );
    HALLCURRENT3_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    hallcurrent3_init( &hallcurrent3, &cfg );
}

void application_task ( )
{
    float current_data;

    current_data = hallcurrent3_get_current( &hallcurrent3 );
    log_printf( &logger, "Current : %f mA\r\n", current_data );

    Delay_ms ( 1000 );
}

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