Intermediate
30 min

Experience real-time current insights with ACS711 and PIC32MZ2048EFH144

Hall Effect's pinpoint accuracy at your service!

Hall current 2 Click with UNI Clicker

Published Aug 10, 2023

Click board™

Hall current 2 Click

Dev Board

UNI Clicker

Compiler

NECTO Studio

MCU

PIC32MZ2048EFH144

Empower your solution to respond swiftly to fluctuations in current behavior thanks to our solution's real-time monitoring capabilities and precision-driven data

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Hardware Overview

How does it work?

Hall Current 2 Click is based on the ACS711, a Hall effect linear current sensor with overcurrent fault output for less than 100 V Isolation Applications, from Allegro Microsystems. This sensor utilizes the Hall effect phenomenon to measure the current passing through the internally fused input pins of the IC. This allows the series resistance to stay very low. Current flow through the input rails of the IC generates a magnetic field, causing the Hall effect on the current flow through the integrated sensor. The resulting voltage is further conditioned and offset by the internal sections of the ACS711 IC, and after the conditioning, it appears at the output of the VIOUT pin. The output voltage changes linearly with the input current in steps of 110mV/A. The output voltage is passed through the buffering circuit comprising the LM358 - a low-noise operational amplifier in a unity gain configuration to allow conversion via the external ADC. The output of this buffer network is connected to the AN pin of the mikroBUS™, allowing an external AD

conversion or utilizing the output voltage in some other way. The response time of the output voltage is very short - in a magnitude of microseconds. 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 22.3 kps, which allows good measurement resolution for most purposes. After the ACS711 output voltage has been converted to a digital value, it can be read via the I2C bus of the MCP3221 ADC. The I2C bus lines are routed to the respective I2C lines of the mikroBUS™ (SCL - clock; SDA - data). The provided library contains functions for simplified reading of the conversion values. The FAULT pin indicates an overcurrent condition. If the measured current exceeds the specified range, this pin will be latched to a LOW logic level. This pin has a fast

response of only 1.3 µs, allowing it to be used as part of the overcurrent protection circuit. Naturally, it can be used as the interrupt pin, triggering an interrupt request on a host MCU. For this reason, it is routed to the INT pin of the mikroBUS™. However, once latched, the ACS711 IC requires power cycling to release the FAULT pin. This can be done by pulling the RST pin of the mikroBUS™ to a HIGH logic level. This will cut the power through the PNP BJT. Pulling the RST pin to a LOW logic level will allow current flow through the BJT again; thus, the ACS711 will release the FAULT pin. The RST pin should stay at the LOW logic level for normal operation. The onboard SMD jumper allows selection between 3.3V and 5V. This allows 3.3V and 5V MCUs to communicate with Hall Current 2 Click. The ACS711 IC offers galvanic isolation for up to 100V. Care should be taken when operating with high voltages, not touching the Click board™.

Hall current 2 Click hardware overview image
Hall Current 2 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

default

Type

8th Generation

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

144

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

Analog Output
PB11
AN
Reset
PH2
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
PD0
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PA2
SCL
I2C Data
PA3
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

Hall current 2 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 Hall Current 2 Click driver.

Key functions:

  • hallcurrent2_generic_read - This function reads data from the desired register

  • hallcurrent2_reset - This function changes reset chip states to reset the chip

  • hallcurrent2_get_current - Reads current's value in mV

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 
 * \brief HallCurrent2 Click example
 * 
 * # Description
 * This application very accurately measures current using Hall effect.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes Driver init and reset chip
 * 
 * ## Application Task  
 * Reads current and logs on usbuart every 1 second.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "hallcurrent2.h"

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

static hallcurrent2_t hallcurrent2;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    hallcurrent2_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.

    hallcurrent2_cfg_setup( &cfg );
    HALLCURRENT2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    hallcurrent2_init( &hallcurrent2, &cfg );

    hallcurrent2_reset( &hallcurrent2 );
}

void application_task ( void )
{
    int16_t current_data;

    current_data = hallcurrent2_get_current( &hallcurrent2 );
    log_printf( &logger, "--- Current : %d mA\r\n", current_data );
    Delay_ms( 1000 );
}

void main ( void )
{
    application_init( );

    for ( ; ; )
    {
        application_task( );
    }
}


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

Additional Support

Resources