Attain accurate and real-time absolute angular positioning with MA302 and ATmega1284P

From 0 to 60.000 RPM: Accurate angle measurement simplified

Published Nov 01, 2023

Click board™

Angle 5 Click

Dev. board

EasyAVR v7

Compiler

NECTO Studio

MCU

ATmega1284P

Detect the absolute rotor position of brushless motors with ease, allowing for seamless control and optimization of motor performance

Hardware Overview

How does it work?

Angle 5 Click is based on the MA302, a 12-bit digital contactless angle sensor with ABZ and UVW incremental outputs from Monolithic Power Systems. This Click board™ can detect the absolute rotor position of a Brushless motor in real-time, even without a target magnet, by measuring the fringe field of the rotor. The sensor must be positioned at the correct place (in this case, below the rotor) to get the maximum value of the rotor magnetic field without being disturbed by other fields. The rotor magnetic field is then measured, and an adequate position was determined from that information. It uses the SPI serial interface for digital angle readout and configuration alongside a programmable magnetic field strength detection function for diagnostic checks. The magnetic field is detected with integrated Hall devices located in the center of the package. The angle is measured using the Spinaxis™ method, based on phase detection,

and generates a sinusoidal signal with a phase that represents the angle of the magnetic field. The angle is then obtained by a time-to-digital converter, which measures the time between the zero-crossing of the sinusoidal signal and the edge of a constant waveform. The time-to-digital represents an output from the front end to the digital conditioning block. This output delivers a digital number proportional to the angle of the magnetic field at the rate of 1MHz in a straightforward and open-loop manner. The Angle 5 Click communicates with MCU using the standard SPI serial interface for angle reading and register programming, which supports SPI Mode 0 and 3 and operates at clock rates up to 25 MHz. It also has the magnetic flags used for indication when the magnetic field at the sensor position is out of range, defined by the lower and upper magnetic field thresholds, routed on the PWM and INT pin of the mikroBUS™ socket labeled as MGH

and MGL. This Click board™ possesses an incremental encoder and block commutation function that uses three output pins each: ABZ and UVW. The ABZ output emulates a 10-bit incremental encoder (such as an optical encoder) providing logic pulses in quadrature, while the UVW output emulates the three Hall switches usually used for the block commutation of a three-phase electric motor. The ABZ and UVW pins of the MA302 are routed on two standard 2.54 mm (0.1 inches) pitch 1x3 header mounted on the Angle 5 Click so an external application can easily access it. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it 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)

128

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

16384

You complete me!

Accessories

2207V-2500kV BLDC Motor is an outrunner brushless DC motor with a kV rating of 2500 and an M5 shaft diameter. It is an excellent solution for fulfilling many functions initially performed by brushed DC motors or in RC drones, racing cars, and much more.

Used MCU Pins

mikroBUS™ mapper

RST

SPI Chip Select

PA5

SPI Clock

PB7

SCK

SPI Data OUT

PB6

MISO

SPI Data IN

PB5

MOSI

Power Supply

3.3V

Ground

GND

Magnetic Field Strength Detection (HIGH)

PD4

PWM

Magnetic Field Strength Detection (LOW)

PD2

INT

SCL

SDA

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 5 Click driver.

Key functions:

angle5_read_raw_angle - Use this function to read raw angle data
angle5_read_angle_deg - Use this function to read angle data

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 
 * \brief Angle5 Click example
 * 
 * # Description
 * Angle 5 click is a magnetic rotational sensor. 
 * It communicates with the target microcontroller over SPI interface.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver.
 * 
 * ## Application Task  
 * Reads the angle position of the magnet and displays the results on the USB UART.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "angle5.h"

// ------------------------------------------------------------------ VARIABLES

static angle5_t angle5;
static log_t logger;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    angle5_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.

    angle5_cfg_setup( &cfg );
    ANGLE5_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    angle5_init( &angle5, &cfg );
}

void application_task ( void )
{
    float new_angle = 0;
    
    new_angle = angle5_read_angle_deg( &angle5 );
    log_printf( &logger, "Angle: %.2f\r\n", new_angle );

    Delay_ms( 100 );
}

void main ( void )
{
    application_init( );

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


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