Beginner
10 min

Fine-tune performance with unipolar Hall switch, the US5881 and STM32G071RB

Unipolar brilliance

UNI HALL Click with Nucleo 64 with STM32G071RB MCU

Published Oct 08, 2024

Click board™

UNI HALL Click

Dev. board

Nucleo 64 with STM32G071RB MCU

Compiler

NECTO Studio

MCU

STM32G071RB

Elevate your design with high-performance Hall switch technology

A

A

Hardware Overview

How does it work?

UNI HALL Click is based on the US5881, a unipolar Hall-effect switch designed in mixed signal CMOS technology from Melexis Technologies. The US5881 comes with very low magnetic sensitivity based on mixed-signal CMOS technology. It 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. Its sensitivity enables high accuracy in position sensing by using a small air gap, making it suitable for various automotive, consumer, and industrial applications. The US5881

exhibits unipolar magnetic switching characteristics. Therefore, it operates only with one magnetic pole – North. Applying a North magnetic pole greater than a magnetic operating point of 25mT, facing the branded side of the package, switches the output of the US5881 to a LOW logic state. 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

switches the output HIGH. The opposite magnetic pole facing the branded side does not affect the output state. 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.

UNI HALL Click hardware overview image

Features overview

Development board

Nucleo-64 with STM32G071RB MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin

headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is

provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.

Nucleo 64 with STM32G071RB MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M0

MCU Memory (KB)

128

Silicon Vendor

STMicroelectronics

Pin count

64

RAM (Bytes)

36864

You complete me!

Accessories

Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.

Click Shield for Nucleo-64 accessories 1 image

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
PC14
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

Click board™ Schematic

UNI HALL Click Schematic schematic

Step by step

Project assembly

Click Shield for Nucleo-64 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo 64 with STM32G071RB MCU as your development board.

Click Shield for Nucleo-64 front image hardware assembly
Nucleo 64 with STM32F401RE MCU front image hardware assembly
EEPROM 13 Click front image hardware assembly
Prog-cut hardware assembly
Nucleo-64 with STM32XXX MCU MB 1 Mini B Conn - 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
Clicker 4 for STM32F4 HA 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 UNI Hall Click driver.

Key functions:

  • unihall_detecting_magnetic_fields - Detecting North pole magnetic fields status function

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 UNI HALL Click example
 * 
 * # Description
 * This is a example which demonstrates the use of UNI HALL Click board.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initialization driver enable's - GPIO and start write log.
 * 
 * ## Application Task  
 * Detect the north pole magnetic fields near the UNI 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 Mikroe Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "unihall.h"

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

static unihall_t unihall;
static log_t logger;

static uint8_t unihall_state;
static uint8_t unihall_state_old;

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


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

void application_init ( void )
{
    log_cfg_t log_cfg;
    unihall_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.

    unihall_cfg_setup( &cfg );
    UNIHALL_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    unihall_init( &unihall, &cfg );

    unihall_state = UNIHALL_NORTH_POLE_DETECTED;
    unihall_state_old = UNIHALL_NORTH_POLE_DETECTED;

    log_printf(&logger, "---------------------------\r\n");
    log_printf(&logger, "        Initialization     \r\n");
    log_printf(&logger, "---------------------------\r\n");
    log_printf(&logger, " Detecting magnetic fields \r\n");
    log_printf(&logger, "---------------------------\r\n");

    Delay_ms ( 100 );
}

void application_task ( void )
{
    unihall_state = unihall_detecting_magnetic_fields( &unihall );

    if ( ( unihall_state == UNIHALL_NORTH_POLE_NOT_DETECTED ) && ( unihall_state_old == UNIHALL_NORTH_POLE_DETECTED ) )
    {
        unihall_state_old = UNIHALL_NORTH_POLE_NOT_DETECTED;
        log_printf(&logger, "      ~ NOT DETECTED ~\r\n");
    }

    if ( ( unihall_state == UNIHALL_NORTH_POLE_DETECTED ) && ( unihall_state_old == UNIHALL_NORTH_POLE_NOT_DETECTED ) )
    {
        
        log_printf(&logger, "        ~ DETECTED ~\r\n");
        unihall_state_old = UNIHALL_NORTH_POLE_DETECTED;
    }
}

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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