Find the angular position of the magnet with AS5070A and ATmega644P

What's your angle?

Published Mar 02, 2023

Click board™

Angle 10 Click

Dev. board

EasyAVR v7

Compiler

NECTO Studio

MCU

ATmega644P

Detect the amount of the magnet's angle change

Hardware Overview

How does it work?

Angle 10 Click is based on the AS5070A, a Hall-based rotary magnetic position sensor using a CMOS technology from ams AG. The lateral Hall sensor array converts the magnetic field component, perpendicular to the surface of the chip, into a voltage. The signals from 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. The AS5070A provides a linear analog ratiometric output signal, which is the angular orientation of the magnet above the AS5070A on a linear absolute scale (ratiometric up to 5V). The analog output voltage of the AS5070A is then sent directly to an analog pin of the mikroBUS™ socket labeled as AN. 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 only be operated with a 5V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Features overview

Development board

EasyAVR v7 is the seventh generation of AVR development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 16-bit AVR microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB. 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, EasyAVR v7 allows you to connect accessory boards, sensors, and custom electronics more

efficiently than ever. Each part of the EasyAVR 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 a wide range of external power sources, including an external 12V power supply, 7-12V AC or 9-15V 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 which cover a wide range of 16-bit AVR MCUs. EasyAVR 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.

Microcontroller Overview

MCU Card / MCU

Architecture

AVR

MCU Memory (KB)

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

4096

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.

Used MCU Pins

mikroBUS™ mapper

Analog Signal

PA7

RST

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

EasyAVR v7 front image hardware assembly

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

NECTO Output Selection Step Image hardware assembly

In the advanced settings, pay special attention to the Redirect standard output field. By default, it is set to Application output as the method of displaying final results. To show results via a UART terminal, select the “UART” option in that field and click the “SAVE” button. You will be returned to the Compiler field, and now you can move on to the next step by pressing the “NEXT” button.

GNSS2 Click front image hardware assembly

GNSS2 Click complete accessories setup image hardware assembly

EasyAVR v7 Access DIP MB 1 - upright/background hardware assembly

NECTO Compiler Selection Step Image hardware assembly

Necto DIP image step 7 hardware assembly

EasyPIC PRO v7a Display Selection 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 Angle 10 Click driver.

Key functions:

angle10_read_voltage This function reads raw ADC value and converts it to proportional voltage level.
angle10_get_angle This function reads the magnetic angular position in degrees based on @b ANGLE10_NUM_CONVERSIONS of voltage measurements.
angle10_set_vref This function sets the voltage reference for Angle 10 click driver.

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 main.c
 * @brief Angle 10 Click Example.
 *
 * # Description
 * This example demonstrates the use of Angle 10 click board by reading and displaying
 * the magnet's angular position in degrees and analog voltage output.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and logger.
 *
 * ## Application Task
 * Reads the magnet's angular position in degrees and analog voltage output 
 * and displays the results on the USB UART approximately every 500ms.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "angle10.h"

static angle10_t angle10;   /**< Angle 10 Click driver object. */
static log_t logger;    /**< Logger object. */

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    angle10_cfg_t angle10_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.
    angle10_cfg_setup( &angle10_cfg );
    ANGLE10_MAP_MIKROBUS( angle10_cfg, MIKROBUS_1 );
    if ( ADC_ERROR == angle10_init( &angle10, &angle10_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    float voltage, angle;
    if ( ANGLE10_OK == angle10_read_voltage ( &angle10, &voltage ) ) 
    {
        log_printf( &logger, " AN Voltage : %.3f V\r\n", voltage );
    }
    if ( ANGLE10_OK == angle10_get_angle ( &angle10, &angle ) )
    {
        log_printf ( &logger, " Angle: %.2f Degrees\r\n\n", angle );
    }
    Delay_ms( 500 );
}

void main ( void ) 
{
    application_init( );

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

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