Intermediate
30 min
0

Experience the freedom of accurate angular measurement with AS5247U and PIC18F26K20

Unlocking angular insights: The ultimate solution for 360-degree magnet rotation

Magnetic Rotary 6 Click with EasyPIC v8

Published Nov 01, 2023

Click board™

Magnetic Rotary 6 Click

Development board

EasyPIC v8

Compiler

NECTO Studio

MCU

PIC18F26K20

Experience unparalleled accuracy in angular measurement with our innovative sensor, capable of tracking magnet rotation over the entire 360-degree spectrum

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Hardware Overview

How does it work?

Magnetic Rotary 6 Click is based on the AS5247U, a high-resolution dual rotary position sensor for fast absolute angle measurement over a full 360-degree range from ams AG. The core of the AS5247U represents a CMOS technology Hall-effect magnetic sensor that converts the magnetic field component perpendicular to the surface of the chip into a digital value. It supports high-speed applications up to 28krpm and allows a host MCU to read 14-bit absolute angle position data and to program non-volatile settings without a dedicated programmer. The AS5247U is also equipped with a Dynamic Angle Error Compensation block that corrects the calculated angle regarding latency by using a linear prediction calculation algorithm. The AS5247U communicates with the MCU using a standard SPI interface. The signals from its internal Hall sensors are amplified and filtered before their conversion

by the ADC and then processed by the CORDIC block to compute the angle and magnitude of the magnetic field vector. The intensity of the magnetic field is used by the automatic gain control (AGC) to adjust the amplification level to compensate for temperature and magnetic field variations. This Click board™ also comes with onboard headers reserved for incremental and commutation signals of their respective A/B/I and U/V/W signals alongside embedded self-diagnostics. Incremental movements are indicated on a set of ABI signals with a maximum resolution of 16384 steps / 4096 pulses per revolution. The resolution of the ABI signal is programmable for 10 to 14 bits. Brushless DC (BLDC) motors are also controllable through a standard UVW commutation interface with a programmable number of pole pairs from 1 to 7. At constant rotation speed, the latency time is

internally compensated by the AS5247U, reducing the dynamic angle error at the SPI, ABI, and UVW outputs. The AS5047D also allows selection between a UVW output interface and a PWM-encoded interface on the W pin, which can be seen as an absolute angle position. A unique addition to this board is a position for a rotary magnet holder designed to be used alongside a magnetic rotary position sensor, allowing fast prototyping and quick measurements during development. 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.

Magnetic Rotary 6 Click top side image
Magnetic Rotary 6 Click bottom side image

Features overview

Development board

EasyPIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports many high pin count 8-bit PIC microcontrollers from Microchip, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer. 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, EasyPIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the EasyPIC v8 development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board 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 DEVICE, and CAN are also included, including the well-established mikroBUS™ standard, two display options (graphical and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from the smallest PIC MCU devices with only eight up to forty pins. EasyPIC 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.

EasyPIC v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

64

Silicon Vendor

Microchip

Pin count

28

RAM (Bytes)

3936

You complete me!

Accessories

Rotary Magnetic Holder is an addition designed for use alongside a magnetic rotary position sensor. It comes with a plastic stand measuring 22x16x10 millimeters (L x W x H), as well as an adjustable shaft with a 6mm diameter magnet. The plastic frame has four round feet that fit into holes in the board near the magnetic rotary position sensor, with a 6mm diameter hole on top to match the adjustable shaft that carries the magnet. This shaft has a height adjustment screw on it, allowing the user to adjust it between 18 and 22 millimeters. This way, fast prototyping and quick measurements of the magnet characteristics are allowed during development.

Magnetic Rotary 6 Click accessories image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
SPI Chip Select
RA5
CS
SPI Clock
RC3
SCK
SPI Data OUT
RC4
MISO
SPI Data IN
RC5
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
External Sync
RC1
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
2

Take a closer look

Schematic

Magnetic Rotary 6 Click Schematic schematic

Step by step

Project assembly

EasyPIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v8 as your development board.

EasyPIC v8 front image hardware assembly
LTE IoT 5 Click front image hardware assembly
MCU DIP 28 hardware assembly
LTE IoT 5 Click complete accessories setup image hardware assembly
EasyPIC v8 28pin-DIP Access - 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
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 Magnetic Rotary 6 Click driver.

Key functions:

  • magneticrotary6_write_register - This function writes a desired data to the selected register of a desired sensor die by using SPI serial interface

  • magneticrotary6_get_angle - This function reads the absolute position raw data of a desired sensor die and converts it to degrees (Angle)

  • magneticrotary6_set_direction - This function sets the rotation direction of a desired sensor die

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 MagneticRotary6 Click example
 *
 * # Description
 * This example demonstrates the use of Magnetic Rotary 6 click board by reading and displaying
 * the magnet's angular position in degrees measured by the bottom and top sensor dies.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs the click default configuration which sets the magnet
 * rotation direction for the bottom die to clockwise and for the top die to counter-clockwise.
 *
 * ## Application Task
 * Reads the magnet's angular position from both sensor dies in degrees every 100ms and displays
 * the results on the USB UART.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "magneticrotary6.h"

static magneticrotary6_t magneticrotary6;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    magneticrotary6_cfg_t magneticrotary6_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_info( &logger, " Application Init " );

    // Click initialization.
    magneticrotary6_cfg_setup( &magneticrotary6_cfg );
    MAGNETICROTARY6_MAP_MIKROBUS( magneticrotary6_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == magneticrotary6_init( &magneticrotary6, &magneticrotary6_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( MAGNETICROTARY6_ERROR == magneticrotary6_default_cfg ( &magneticrotary6 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }

    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    float angle;
    if ( MAGNETICROTARY6_OK == magneticrotary6_get_angle ( &magneticrotary6, MAGNETICROTARY6_DIE_BOTTOM, &angle ) )
    {
        log_printf( &logger, " Angle (bottom die): %.1f degrees\r\n", angle );
    }
    if ( MAGNETICROTARY6_OK == magneticrotary6_get_angle ( &magneticrotary6, MAGNETICROTARY6_DIE_TOP, &angle ) )
    {
        log_printf( &logger, " Angle (top die): %.1f degrees\r\n\n", angle );
    }
    Delay_ms ( 100 );
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources