Intermediate
30 min

Provide unparalleled accuracy and versatility in magnetic field detection using RedRock™ TMR sensors and STM32F031K6

TMR sensors with field intensity insight

TMR mix-sens click with Nucleo 32 with STM32F031K6 MCU

Published Oct 01, 2024

Click board™

TMR mix-sens click

Dev. board

Nucleo 32 with STM32F031K6 MCU

Compiler

NECTO Studio

MCU

STM32F031K6

Experience the future of magnetic sensing with our TMR-equipped solution, offering both push-pull and analog capabilities, as well as real-time magnetic field intensity visualization, perfect for applications demanding high precision

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Hardware Overview

How does it work?

TMR mix-sens Click is based on three different TMR magnetic sensors from Coto Technology that can be operated with supplied magnets and provide instantaneous visual feedback through LEDs that indicate sensor output. The first sensor on this Click board, the RR121-1A23-311, is a monopolar, 9 Gauss operate, 10Hz sensing frequency, push-pull output sensor that consumes an average of only 240nA. This sensor is often used to detect proximity or signal a battery-operated device to wake up or power on. The second sensor on this Click board is an RR121-3C63-311, a bi-polar, 10 Gauss operate/-10 Gauss release, 500Hz sensing frequency, push-pull output sensor that consumes an average of 1.7uA. This sensor is often used for rotation counting. The third sensor on this Click board is an RR111-1DC2-331 which provides a linear voltage output proportional to a magnetic field strength between -10 and 10 Gauss with a sensitivity of -20 mv/V/G and 1.5mA average supply current. This sensor is typically used in level or

distance-sensing applications and can provide a distance resolution of 1mm. In addition to accessing the outputs of the three sensors through the mikroBUS and getting information to the host MCU, visual confirmation of the activation and deactivation of each sensor is provided using LEDs placed next to each sensor on the board. When operating these sensors with the supplied magnets or magnets of your choosing, the LEDs associated with each sensor will activate to indicate the sensing of a magnetic field visually. The LED2 for the RR121-1A23-311 lights up when the operating field strength of 9 Gauss is reached and turns off when the release field strength of 5 Gauss is reached, providing a hysteresis of 4 Gauss. This can be demonstrated by moving the North or South pole of the magnet toward the sensor in the direction of the arrow. The LED3 for the RR121-3C63-311 lights up when a South pole field with a magnitude of 10 Gauss or greater is sensed and will stay lit until a North pole of 10 Gauss

or higher is sensed. This can be demonstrated by bringing in a magnet with one polarity and then reversing it. It can also be demonstrated by rotating the supplied ring magnet in the hole adjacent to the sensor. The semi-circular array of nine LEDs (LED4-LED12) on the top of the board is used for the RR111-1DC2-331 sensor. Please refer to the image above for the LED numbering. These will indicate when the sensor sees a North, South, or no field and the magnitude for each polarity. The middle LED (LD8) will light to indicate no magnetic field (voltage output of Vdd/2). An LM3914 is used to indicate the strength of the linear output of the RR111-1DC2-331 sensor. The operation of this sensor can be demonstrated by moving the North or South pole of the magnet towards the sensor in the direction of the magnet. Alternatively, it can be demonstrated by rotating the ring magnet in the hole adjacent to the sensor. Holes on the TMR mix-sens can be used to ease the installation of rotatable magnet holders.

TMR mix-sens click hardware overview image

Features overview

Development board

Nucleo 32 with STM32F031K6 MCU board provides an affordable and flexible platform for experimenting with STM32 microcontrollers in 32-pin packages. Featuring Arduino™ Nano connectivity, it allows easy expansion with specialized shields, while being mbed-enabled for seamless integration with online resources. The

board includes an on-board ST-LINK/V2-1 debugger/programmer, supporting USB reenumeration with three interfaces: Virtual Com port, mass storage, and debug port. It offers a flexible power supply through either USB VBUS or an external source. Additionally, it includes three LEDs (LD1 for USB communication, LD2 for power,

and LD3 as a user LED) and a reset push button. The STM32 Nucleo-32 board is supported by various Integrated Development Environments (IDEs) such as IAR™, Keil®, and GCC-based IDEs like AC6 SW4STM32, making it a versatile tool for developers.

Nucleo 32 with STM32F031K6 MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M0

MCU Memory (KB)

32

Silicon Vendor

STMicroelectronics

Pin count

32

RAM (Bytes)

4096

You complete me!

Accessories

Click Shield for Nucleo-32 is the perfect way to expand your development board's functionalities with STM32 Nucleo-32 pinout. The Click Shield for Nucleo-32 provides two mikroBUS™ sockets to add any functionality from our ever-growing range of Click boards™. We are fully stocked with everything, from sensors and WiFi transceivers to motor control and audio amplifiers. The Click Shield for Nucleo-32 is compatible with the STM32 Nucleo-32 board, providing an affordable and flexible way for users to try out new ideas and quickly create prototypes with any STM32 microcontrollers, choosing from the various combinations of performance, power consumption, and features. The STM32 Nucleo-32 boards do not require any separate probe as they integrate the ST-LINK/V2-1 debugger/programmer and come with the STM32 comprehensive software HAL library and various packaged software examples. This development platform provides users with an effortless and common way to combine the STM32 Nucleo-32 footprint compatible board with their favorite Click boards™ in their upcoming projects.

Click Shield for Nucleo-32 accessories 1 image

Used MCU Pins

mikroBUS™ mapper

Magnetic Analog Output
PA0
AN
Digital Omnipolar Output
PA11
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Digital Bipolar Output
PA8
PWM
NC
NC
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

TMR mix-sens click Schematic schematic

Step by step

Project assembly

Click Shield for Nucleo-144 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo 32 with STM32F031K6 MCU as your development board.

Click Shield for Nucleo-144 front image hardware assembly
Nucleo 144 with STM32L4A6ZG MCU front image hardware assembly
Stepper 22 Click front image hardware assembly
Prog-cut hardware assembly
Board mapper by product8 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
STM32 M4 Clicker HA MCU/Select 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 TMR mix-sens Click driver.

Key functions:

  • tmrmixsens_generic_read - Generic read function

  • tmrmixsens_get_omnipolar - Get state of the omnipolar ( OMN ) pin function

  • tmrmixsens_get_bipolar - Get state of the bipolar ( BI ) pin 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 Tmrmixsens Click example
 * 
 * # Description
 * The TMR mix-sens Click has three types of magnetic field sensors: Two digital and one analog sensor. 
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver and logger and makes an initial log.
 * 
 * ## Application Task  
 * Displays the ADC value of linear output and the states of bipolar and omnipolar indicators
 * on the USB UART each second.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "tmrmixsens.h"

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

static tmrmixsens_t tmrmixsens;
static log_t logger;

static uint16_t adc_value;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    tmrmixsens_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.

    tmrmixsens_cfg_setup( &cfg );
    TMRMIXSENS_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    tmrmixsens_init( &tmrmixsens, &cfg );
}

void application_task ( void )
{
    tmrmixsens_data_t tmp;
    
    tmp = tmrmixsens_generic_read ( &tmrmixsens );
    log_printf( &logger, " ADC value of linear output : %d \r\n", tmp );

    log_printf( &logger, " Bipolar response: " );
    if ( tmrmixsens_get_bipolar( &tmrmixsens ) == TMRMIXSENS_NORTH_POLE )
    {
        log_printf( &logger, " North pole is detected!\r\n" );
    }
    else if( tmrmixsens_get_bipolar( &tmrmixsens ) == TMRMIXSENS_SOUTH_POLE )
    {
        log_printf( &logger, " South pole is detected!\r\n" );
    }
    
    if ( tmrmixsens_get_omnipolar ( &tmrmixsens ) == 0 )
    {
        log_printf( &logger, " Omnipolar response: Either South or North pole is detected!\r\n" );
    }
    
    log_printf( &logger, "--------------------------------------\r\n" );
    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

Additional Support

Resources

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