Intermediate
30 min

Provide unparalleled accuracy and versatility in magnetic field detection using RedRock™ TMR sensors and STM32F437ZG

TMR sensors with field intensity insight

TMR mix-sens click with Fusion for ARM v8

Published Aug 13, 2023

Click board™

TMR mix-sens click

Development board

Fusion for ARM v8

Compiler

NECTO Studio

MCU

STM32F437ZG

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

A

A

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

Fusion for ARM v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different ARM® Cortex®-M based MCUs 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 ARM v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the Fusion for ARM v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it 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 ARM 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 ARM v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

ARM Cortex-M4

MCU Memory (KB)

1024

Silicon Vendor

STMicroelectronics

Pin count

144

RAM (Bytes)

262144

Used MCU Pins

mikroBUS™ mapper

Magnetic Analog Output
PA3
AN
Digital Omnipolar Output
PE11
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
PD12
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

Schematic

TMR mix-sens 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 ARM v8 as your development board.

Fusion for PIC v8 front image hardware assembly
Buck 22 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
v8 SiBRAIN 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 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

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

/*!
 * \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 );
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources