Measure the angle of a rotating shaft with ADA4570 and TM4C1299KCZAD
The angle whisperer
Published Apr 06, 2023
Click board™
AMR Angle 2 Click
Dev. board
Fusion for Tiva v8
Compiler
NECTO Studio
MCU
TM4C1299KCZAD
Experience precise and reliable angular position measurement of the surrounding magnetic field with an AMR angle sensor
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Hardware Overview
How does it work?
AMR Angle 2 Click is based on the ADA4570, an anisotropic magnetoresistive (AMR) sensor with integrated signal conditioning amplifiers and analog-to-digital converter (ADC) drivers from Analog Devices. It consists of two dies within one package, an AMR sensor, and a fixed gain instrumentation amplifier producing two differential analog outputs that indicate the angular position of the surrounding magnetic field. These amplified differential cosine and sine output signals are delivered with respect to the angle when the magnetic field is rotating in the x-axis and the y-axis (x-y) plane. The ADA4570 contains two Wheatstone bridges at a relative angle of 45° to one another. A complete rotation of a dipole magnet produces two periods on the sinusoidal outputs, so the magnetic angle calculated from the sine and cosine
differential outputs represents the physical orientation of the magnet with respect to the ADA4570 in the 0° to 180° measurement range. Within a homogeneous field in the x-y plane, the output signals of the ADA4570 are independent of the physical placement in the z-direction (air gap). As mentioned before, alongside the AMR sensor, this Click board™ also contains one high-speed, low-power, serial output successive approximation register (SAR) analog-to-digital converter (ADC), the MAX11122 from Analog Devices. It processes sine and cosine outputs and then forwards them to the MCU via the SPI interface for further processing. Apart from the SPI communication lines, this Click board™ uses several more pins on the mikroBUS™ such as CST and EOC, routed to the PWM and INT pins of the mikroBUS™ socket,
representing the signals with which the AD conversion starts and the signal indicating the completion of the conversion itself, respectively. Also, the ADA4570 has an integrated temperature sensor that provides a voltage ratiometric to the ADA4570 supply voltage at the AN pin of the mikroBUS™ socket used to monitor the system's operating temperature and provide the reference for further calibration. This Click board™ can only be operated with a 3.3V 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
Fusion for TIVA 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 Texas Instruments, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over a WiFi network. 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 TIVA v8 provides a fluid and immersive working experience, allowing access
anywhere and under any circumstances at any time. Each part of the Fusion for TIVA 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 TIVA 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.
Microcontroller Overview
MCU Card / MCU
Type
8th Generation
Architecture
ARM Cortex-M4
MCU Memory (KB)
512
Silicon Vendor
Texas Instruments
Pin count
212
RAM (Bytes)
262144
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Fusion for Tiva v8 as your development board.
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 AMR Angle 2 Click driver.
Key functions:
amrangle2_read_angleThis function reads Vsin and Vcos voltages and converts them to angle in Degrees.amrangle2_read_temperatureThis function reads temperature measurements in Celsius.amrangle2_read_vsin_vcosThis function reads a voltage of sine and cosine differential signal outputs.
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 AMR Angle 2 Click example
*
* # Description
* This example demonstrates the use of AMR Angle 2 click board by reading and displaying
* the magnet's angular position in Degrees and a system temperature in Celsius.
*
* 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 a system temperature in Celsius
* and displays the results on the USB UART approximately every 100ms.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "amrangle2.h"
static amrangle2_t amrangle2;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
amrangle2_cfg_t amrangle2_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.
amrangle2_cfg_setup( &amrangle2_cfg );
AMRANGLE2_MAP_MIKROBUS( amrangle2_cfg, MIKROBUS_1 );
if ( SPI_MASTER_ERROR == amrangle2_init( &amrangle2, &amrangle2_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( AMRANGLE2_ERROR == amrangle2_default_cfg ( &amrangle2 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float angle, temperature;
if ( AMRANGLE2_OK == amrangle2_read_angle ( &amrangle2, &angle ) )
{
log_printf( &logger, " Angle: %.2f Degrees\r\n", angle );
}
if ( AMRANGLE2_OK == amrangle2_read_temperature ( &amrangle2, &temperature ) )
{
log_printf( &logger, " Temperature: %.2f C\r\n\n", temperature );
}
Delay_ms( 100 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
