Intermediate
30 min

Determine the magnetic field orientation using the AS5600 and STM32F767ZG

Be sure you are in the correct position

Angle 7 Click with Fusion for STM32 v8

Published Feb 17, 2023

Click board™

Angle 7 Click

Dev Board

Fusion for STM32 v8

Compiler

NECTO Studio

MCU

STM32F767ZG

Find the magnet's absolute angular position

A

A

Hardware Overview

How does it work?

Angle 7 Click is based on the AS5600, an easy-to-program magnetic rotary position sensor with a high-resolution 12-bit analog or PWM output from ams AG. The AS5600 is a Hall-based rotary magnetic position sensor using planar sensors that convert the magnetic field component perpendicular to the surface of the chip into a voltage. It measures the absolute angle of a diametric-magnetized on-axis magnet while at the same time rejecting stray magnetic fields. By default, the output represents a range from 18 to 360 degrees. It is also possible to define a smaller range to the output by programming a zero angle (start position) and a maximum angle (stop position). First, the signals coming from internal Hall sensors are amplified and filtered before their conversion by the ADC and then processed by the hardwired 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. After that, the output stage uses the angle value provided by the CORDIC algorithm. The user can choose between an analog output representing the angle as a ratiometric linear absolute value and a digital PWM-encoded output representing the angle as the pulse width. The selection can be made by positioning the SMD jumper labeled OUT SEL in an appropriate position marked as AN or INT. Angle 7 Click communicates with MCU using the standard I2C 2-Wire interface with a maximum clock frequency of 1MHz, fully adjustable through software registers. Also, the DIR SEL jumper allows users to select the polarity of the output relative to rotation direction by positioning the SMD jumper in an appropriate position marked as CW or CCW allowing clockwise or counterclockwise rotation. 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. Both mikroBUS™ power rails have protection in the form of diode MAX40200, controllable through an EN pin on the mikroBUS™ socket to prevent any unwanted back voltage. 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. In the case of using a logic level of 5V, it is necessary first to remove the resistor R6 and then switch the VCC jumper to the 5V position.

angle_7_click_hardware_overview

Features overview

Development board

Fusion for STM32 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 32-bit ARM® Cortex®-M based MCUs from STMicroelectronics, 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 STM32 v8 provides a fluid and immersive working experience, allowing

access anywhere and under any circumstances at any time. Each part of the Fusion for STM32 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 STM32 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 STM32 v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

ARM Cortex-M7

MCU Memory (KB)

1024

Silicon Vendor

STMicroelectronics

Pin count

144

RAM (Bytes)

524288

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.

Angle 7 Click accessories image

Used MCU Pins

mikroBUS™ mapper

Analog Signal
PA3
AN
NC
NC
RST
Enable
PA4
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
PWM Signal
PD3
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB8
SCL
I2C Data
PB9
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

Angle 7 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 STM32 v8 as your development board.

Fusion for PIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
v8 SiBRAIN Access 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 Angle 7 Click driver.

Key functions:

  • angle7_get_status This function reads the status data.

  • angle7_get_angle This function reads the calculated angle in degrees.

  • angle7_get_magnitude This function reads the magnitude data.

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 Angle7 Click example
 *
 * # Description
 * This example demonstrates the use of Angle 7 click board by reading and displaying
 * the magnet's angular position in degrees and analog voltage output as well as
 * the magnet's status and magnitude.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs the click default configuration.
 *
 * ## Application Task
 * Reads the magnet's angular position in degrees and analog voltage output 
 * as well as the magnet's status and magnitude and displays the results on the USB UART
 * approximately every 100ms.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "angle7.h"

static angle7_t angle7;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    angle7_cfg_t angle7_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.
    angle7_cfg_setup( &angle7_cfg );
    ANGLE7_MAP_MIKROBUS( angle7_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == angle7_init( &angle7, &angle7_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( ANGLE7_ERROR == angle7_default_cfg ( &angle7 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    float voltage, raw_angle, angle;
    uint16_t magnitude;
    uint8_t status;
    if ( ADC_ERROR != angle7_read_an_pin_voltage ( &angle7, &voltage ) ) 
    {
        log_printf( &logger, " AN voltage: %.3f V\r\n", voltage );
    }
    if ( ANGLE7_OK == angle7_get_angle ( &angle7, &angle ) )
    {
        log_printf ( &logger, " Angle: %.2f Degrees\r\n", angle );
    }
    if ( ANGLE7_OK == angle7_get_magnitude ( &angle7, &magnitude ) )
    {
        log_printf ( &logger, " Magnitude: %u\r\n", magnitude );
    }
    if ( ANGLE7_OK == angle7_get_status ( &angle7, &status ) )
    {
        log_printf ( &logger, " Status:" );
        if ( status & ANGLE7_STATUS_MAGNET_DETECTED )
        {
            log_printf ( &logger, " Magnet Detected \r\n Magnet Strength:" );
            if ( status & ANGLE7_STATUS_MAGNET_TOO_STRONG )
            {
                log_printf ( &logger, " Too Strong \r\n\n" );
            }
            else if ( status & ANGLE7_STATUS_MAGNET_TOO_WEAK )
            {
                log_printf ( &logger, " Too Weak \r\n\n" );
            }
            else
            {
                log_printf ( &logger, " Good \r\n\n" );
            }
        }
        else
        {
            log_printf ( &logger, " Magnet Not Detected \r\n\n" );
        }
    }
    Delay_ms ( 100 );
}

void main ( void ) 
{
    application_init( );

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

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

Additional Support

Resources