Intermediate
30 min
0

Experience unparalleled precision in magnetic angle measurement with our KMZ60 and PIC18LF4455

Magnetoresistive marvel: Your go-to sensor for magnetic angle measurement

MR Angle Click with EasyPIC v7

Published Nov 01, 2023

Click board™

MR Angle Click

Development board

EasyPIC v7

Compiler

NECTO Studio

MCU

PIC18LF4455

Redefine angle measurement with ease using our advanced magnetoresistive technology, delivering precise results through single-ended cosine and sine outputs

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Hardware Overview

How does it work?

MR Angle Click is based on the KMZ60, a high-precision sensor for magnetic angle measurement from NXP Semiconductors. The integrated MR sensor element, a sensitive magnetic field sensor, employs the MR effect of thin-film permalloy. The sensor contains two parallel supplied Wheatstone bridges enclosing a sensitive angle of 45 degrees. A rotating magnetic field in the surface parallel to the chip (x-y plane) will deliver two independent sinusoidal output signals, one following a cosine and the second following a sine function. It also comes with a Power-Down mode to turn on or off the device and a possibility for the temperature coefficient of the sensor amplitude to be compensated. MR Angle Click communicates with MCU through the SPI serial interface using the

MCP3204, a 12-bit 4-channel A/D converter from Microchip. The output sine and cosine signals from the KMZ60 are wired as pseudo-differential input signals to the MCP3204. The MCP3204 samples both sensor channels simultaneously using an SPI interface, allowing access to both channels on one data line. Besides, it possesses additional functionality routed on two GPIO pins, such as Power-Down mode and temperature compensation. The KMZ60 can be used as specified with the temperature compensation of the MR sensor signal. Pin TCE enables the temperature compensation, routed on the RST pin of the mikroBUS™ socket (connected to the ground if no temperature compensation is required). The output signal amplitude will

decrease with increasing temperature related to the temperature compensation of the MR sensor. The Power-Down feature labeled as PDN and routed on the PWM pin of the mikroBUS™ socket switches the device into Power-Down mode and sets the sine and cosine outputs in a high impedance state to avoid current consumption. 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.

MR Angle Click top side image
MR Angle Click bottom side image

Features overview

Development board

EasyPIC v7 is the seventh generation of PIC development boards specially designed to develop embedded applications rapidly. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB-B. The development board is well organized and designed so that the end-user has all the necessary elements in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyPIC v7 allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of

the EasyPIC v7 development board contains the components necessary for the most efficient operation of the same board. An integrated mikroProg, a fast USB 2.0 programmer with mikroICD hardware In-Circuit Debugger, offers many valuable programming/debugging options and seamless integration with the Mikroe software environment. Besides it also includes a clean and regulated power supply block for the development board. It can use various external power sources, including an external 12V power supply, 7-23V AC or 9-32V DC via DC connector/screw terminals, and a power source via the USB Type-B (USB-B) connector. Communication options such as

USB-UART and RS-232 are also included, alongside the well-established mikroBUS™ standard, three display options (7-segment, graphical, and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from PIC10F, PIC12F, PIC16F, PIC16Enh, PIC18F, PIC18FJ, and PIC18FK families. EasyPIC v7 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.

EasyPIC v7 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

24

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

2048

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Temperature Compensation
RE1
RST
SPI Chip Select
RE0
CS
SPI Clock
RC3
SCK
SPI Data OUT
RC4
MISO
SPI Data IN
RC5
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Power-Down Mode
RC0
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

MR Angle Click Schematic schematic

Step by step

Project assembly

EasyPIC v7 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v7 as your development board.

EasyPIC v7 front image hardware assembly
Buck 22 Click front image hardware assembly
MCU DIP 40 hardware assembly
EasyPIC v7 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 DIP image step 7 hardware assembly
EasyPIC PRO v7a Display Selection Necto Step 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 MR Angle Click driver.

Key functions:

  • mrangle_get_angle - MR Angle get angle function

  • mrangle_get_temperature - MR Angle get temperature function

  • mrangle_powerdown_mode - MR Angle powerdown mode 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 MrAngle Click example
 *
 * # Description
 * This library contains API for the MR Angle click driver.
 * This demo application shows an example of angle measurement.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization of SPI module and log UART.
 * After driver initialization, the app performs default settings.
 *
 * ## Application Task
 * This is an example that shows the use of an MR Angle click board™.
 * The application task consists of reading the angle measurements in degrees ( 0 - 180 ).
 * Results are being sent to the Usart Terminal where you can track their changes.
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "mrangle.h"

static mrangle_t mrangle;
static log_t logger;
static float angle;

void application_init ( void ) {
    log_cfg_t log_cfg;          /**< Logger config object. */
    mrangle_cfg_t mrangle_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_printf( &logger, "\r\n" );
    log_info( &logger, " Application Init " );

    // Click initialization.

    mrangle_cfg_setup( &mrangle_cfg );
    MRANGLE_MAP_MIKROBUS( mrangle_cfg, MIKROBUS_1 );
    err_t init_flag  = mrangle_init( &mrangle, &mrangle_cfg );
    if ( init_flag == SPI_MASTER_ERROR ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    mrangle_default_cfg ( &mrangle );
    log_info( &logger, " Application Task " );
    log_printf( &logger, "-------------------------\r\n" );
    Delay_ms( 1000 );
}

void application_task ( void ) {
    mrangle_get_angle( &mrangle, &angle );
    log_printf( &logger, "   Angle : %.2f degree   \r\n", angle );
    log_printf( &logger, "-------------------------\r\n" );
    Delay_ms( 1000 );
}

void main ( void ) {
    application_init( );

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

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

Additional Support

Resources