Beginner
10 min

Monitor and respond to changes in the magnetic environment with US2882 and MK64FN1M0VDC12

Add a bipolar hall switch for smoother operations

Bi Hall Click with Clicker 2 for Kinetis

Published Jun 20, 2023

Click board™

Bi Hall Click

Dev.Board

Clicker 2 for Kinetis

Compiler

NECTO Studio

MCU

MK64FN1M0VDC12

By incorporating a bipolar Hall switch solution, you can ensure seamless switching between different states or modes in your design, enhancing its functionality and versatility

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Hardware Overview

How does it work?

BI HALL Click is based on the US2882, a bipolar Hall-effect switch designed in mixed signal CMOS technology from Melexis Technologies. The US2882 comes with very high magnetic sensitivity based on mixed-signal CMOS technology. The US2882 integrates a voltage regulator, a Hall sensor with a dynamic offset cancellation system, a Schmitt trigger, and an open-drain output driver, all in a single package. It allows using generic magnets, weak magnets, or more significant air gaps, making it suitable for various automotive, consumer, and BLDC motor applications. The US2882 exhibits bipolar magnetic switching characteristics. Therefore, it operates with both the South and North poles. Typically, the device

behaves as a latch with symmetric operating and release switching points, which means magnetic fields with equivalent strength and opposite directions drive the output HIGH and LOW. In this way, it is possible to determine the pole of the magnet using the information that the host MCU receives from the sensor via the INT line of the mikroBUS™ socket. It is also possible to visually identify the magnet's North Pole via an onboard red LED. Removing the magnetic field keeps the output in its previous state, which defines the US2882 as a magnetic memory. Depending on the magnetic switching points, the US2882 may also behave as a unipolar positive or negative switch, which means the output can be set to HIGH and LOW by only

using one magnetic pole. In such a case, removing the magnetic field changes the output level. The chopper-stabilized amplifier uses a switched-capacitor technique to suppress the offset generally observed with Hall sensors and amplifiers. The CMOS technology makes this advanced technique possible, resulting in more stable magnetic characteristics. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the LOGIC LEVEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. However, the 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.

Bi Hall Click hardware overview image

Features overview

Development board

Clicker 2 for Kinetis is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit ARM Cortex-M4F microcontroller, the MK64FN1M0VDC12 from NXP Semiconductors, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a JTAG programmer connector, and two 26-pin headers for interfacing with external electronics. Its compact design with clear and easily recognizable silkscreen markings allows you to build gadgets with unique functionalities and

features quickly. Each part of the Clicker 2 for Kinetis development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the Clicker 2 for Kinetis programming method, using a USB HID mikroBootloader or an external mikroProg connector for Kinetis programmer, the Clicker 2 board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Micro-B cable, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or

using a Li-Polymer battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several user-configurable buttons and LED indicators. Clicker 2 for Kinetis 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.

Clicker 2 for Kinetis dimensions image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M4

MCU Memory (KB)

1024

Silicon Vendor

NXP

Pin count

121

RAM (Bytes)

262144

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
Hall Switch Output
PB13
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

Bi Hall Click Schematic schematic

Step by step

Project assembly

Clicker 2 for PIC32MZ front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Clicker 2 for Kinetis as your development board.

Clicker 2 for PIC32MZ front image hardware assembly
Buck 22 Click front image hardware assembly
Prog-cut hardware assembly
Micro B Connector Clicker 2 - 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
Flip&Click PIC32MZ 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

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 BI HALL Click driver.

Key functions:

  • bihall_det_mag_field - Detecting south and north pole magnetic fields status 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 
 * \brief BI HALL Click example
 * 
 * # Description
 * Detect the south & north pole magnetic fields.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Configuring clicks and log objects.
 * 
 * ## Application Task  
 * This is a example which demonstrates the use of BI HALL Click board.
 * Detect the south & north pole magnetic fields near the BI HALL Click.
 * Results are being sent to the Usart Terminal where you can track their changes.
 * All data logs on usb uart when magnetic field is detected.
 * 
 * \author Nenad Filipovic
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "bihall.h"

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

static bihall_t bihall;
static log_t logger;

uint8_t bihall_state;
uint8_t bihall_state_old;

// ------------------------------------------------------- ADDITIONAL FUNCTIONS


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

void application_init ( void )
{
    log_cfg_t log_cfg;
    bihall_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_printf(&logger, "---- Application Init ----\r\n");

    //  Click initialization.

    bihall_cfg_setup( &cfg );
    BIHALL_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    bihall_init( &bihall, &cfg );
    
    log_printf(&logger, " Detecting magnetic fields\r\n");
    log_printf(&logger, "--------------------------\r\n");
    
    bihall_state = BIHALL_MAG_POLE_NORTH;
    bihall_state_old = BIHALL_MAG_POLE_NORTH;
}

void application_task ( void )
{
    bihall_state = bihall_det_mag_field( &bihall );

    if ( ( bihall_state == BIHALL_MAG_POLE_SOUTH ) && ( bihall_state_old == BIHALL_MAG_POLE_NORTH ) )
    {
        bihall_state_old = BIHALL_MAG_POLE_SOUTH;
        log_printf(&logger, "         ~ SOUTH ~\r\n");
        log_printf(&logger, "--------------------------\r\n");
    }

    if ( ( bihall_state == BIHALL_MAG_POLE_NORTH ) && ( bihall_state_old == BIHALL_MAG_POLE_SOUTH ) )
    {
        log_printf(&logger, "         ~ NORTH ~\r\n");
        log_printf(&logger, "--------------------------\r\n");
        bihall_state_old = BIHALL_MAG_POLE_NORTH;
    }
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources