Intermediate
30 min

Attain unparalleled accuracy in measuring AC or DC currents using PIC32MX695F512L and ACS770

Transforming applications with current sensing

Hall Current 7 Click with Fusion for PIC32 v8

Published Aug 12, 2023

Click board™

Hall Current 7 Click

Dev Board

Fusion for PIC32 v8

Compiler

NECTO Studio

MCU

PIC32MX695F512L

Navigate complex current flows confidently with our Hall-effect sensing solution, enabling you to understand current behavior and make informed adjustments to enhance system efficiency

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Hardware Overview

How does it work?

Hall Current 7 Click is based on the ACS770, a thermally enhanced, fully integrated, Hall effect-based high precision linear current sensor with 100µΩ current conductor from Allegro MicroSystems. This Hall-effect current sensor eliminates the need for a sense-resistor. The current flows directly into the integrated conductor, generating a magnetic field that will be measured. As current flows in its integrated conductor, an integrated low-hysteresis core concentrates the magnetic field that is then sensed by the Hall element with a typical accuracy of ±1% and 120 kHz bandwidth. This core also acts as a magnetic shield, rejecting external stray fields. The integrated conductor has 100μΩ resistance, providing ultralow-power loss. The copper

conductor's thickness allows the device's survival at high overcurrent conditions. The terminals of the conductive path are electrically isolated from the signal leads. This enables the ACS770 to be used in applications requiring electrical isolation without optoisolators or other costly isolation techniques. The ACS770 outputs an analog signal that varies linearly with the bidirectional AC or DC primary sampled current. The analog signal is then brought to the analog-to-digital converter (ADC) that converts the output signal from the ACS770 into a digital value, available over the I2C interface. Hall Current 7 Click communicates with MCU through the MCP3221, a successive approximation A/D converter with a 12-bit resolution from Microchip, using a 2-wire I2C compatible interface. This

device provides one single-ended input with low power consumption, a low maximum conversion current, and a Standby current of 250 μA and 1 μA, respectively. Data can be transferred at 100kbit/s in the Standard and 400 kbit/s in the Fast Mode. Also, maximum sample rates of 22.3 kSPS with the MCP3221 are possible in a Continuous-Conversion Mode with a clock rate of 400 kHz. 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.

Hall Current 7 Click hardware overview image
Hall Current 7 Click Current Warning image

Features overview

Development board

Fusion for PIC32 v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of Microchip's PIC32 microcontrollers regardless of their number of pins and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. 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 PIC32 v8 provides a fluid and immersive working experience, allowing access anywhere and under any circumstances at any time. Each part of the

Fusion for PIC32 v8 development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board 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 PIC32 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.

Fusion for PIC32 v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

PIC32

MCU Memory (KB)

512

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

131072

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
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
NC
NC
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 7 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 PIC32 v8 as your development board.

Fusion for PIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
v8 SiBRAIN 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 Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART Application Output Step 4

Software Support

Library Description

This library contains API for Hall Current 7 Click driver.

Key functions:

  • hallcurrent7_read_voltage - Read voltage function

  • hallcurrent7_calc_current - Calculate current function

  • hallcurrent7_avg_current - Calculate average current function

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 main.c
 * @brief HallCurrent7 Click example
 *
 * # Description
 * This example shows the capabilities of the Hall Current 7 click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initalizes I2C driver and makes an initial log.
 *
 * ## Application Task
 * Measuring current passing through the on board Hall Effect Sensor and 
 * displaying data every two seconds. 
 *
 * @note
 * In order to get correct calculations user should change "v_ref" 
 * value to his own power supply voltage.
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "hallcurrent7.h"

static hallcurrent7_t hallcurrent7;
static log_t logger;

int16_t current;

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    hallcurrent7_cfg_t hallcurrent7_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.
    hallcurrent7_cfg_setup( &hallcurrent7_cfg );
    HALLCURRENT7_MAP_MIKROBUS( hallcurrent7_cfg, MIKROBUS_1 );
    err_t init_flag = hallcurrent7_init( &hallcurrent7, &hallcurrent7_cfg );
    if ( I2C_MASTER_ERROR == init_flag ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    log_info( &logger, " Application Task " );
}

void application_task ( void ) {
    current = hallcurrent7_avg_current( &hallcurrent7, HALLCURRENT7_VREF_5000_mV );
    log_printf( &logger, "Current: %d mA\r\n", current );

    log_printf( &logger, "------------------------\r\n" );
    Delay_ms( 2000 );
}

void main ( void ) {
    application_init( );

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

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

Additional Support

Resources