Monitor the movement of critical magnetic components using A1359 and PIC18F67K40
Contactless magnetic position sensing
Published Sep 28, 2023
Click board™
Magneto 9 Click
Dev. board
Clicker 2 for PIC18FK
Compiler
NECTO Studio
MCU
PIC18F67K40
Experience the future of magnetic sensing technology with our innovative solution, designed to monitor magnetic fields, magnet motion, and rotational angles for a wide range of applications
A
A
Hardware Overview
How does it work?
Magneto 9 Click is based on the A1359, a one-time programmable, dual tracking output, linear Hall-effect sensor from Allegro MicroSystems. It provides a dual analog/PWM output, where the PWM output tracks the analog output to within a +/-3% mismatch. It comes with factory-programmed output polarity; in this case, a forward polarity, meaning that output voltage increases with increasing positive (south) applied magnetic field. The A1359 targets the automotive market with end applications, including electronic power steering (torque sensing), transmission component position, brake and clutch cylinder
position, and various other industrial applications. The analog output signal of the A1359 can be converted to a digital value using MCP3221, a successive approximation A/D converter with a 12-bit resolution from Microchip, using a 2-wire I2C compatible interface, or can be sent directly to an analog pin of the mikroBUS™ socket labeled as AN. Selection can be performed by onboard SMD jumper labeled AD SEL to an appropriate position marked as AN and ADC. The MCP3221 provides one single-ended input with low power consumption, a low maximum conversion current, and a Standby current of 250μA and 1μA,
respectively. Data can be transferred at up to 100kbit/s in the Standard and 400kbit/s in the Fast Mode. Also, maximum sample rates of 22.3kSPS with the MCP3221 are possible in a Continuous-Conversion Mode with a clock rate of 400kHz. This Click board™ can be operated only with a 5V 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
Clicker 2 for PIC18FK is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 8-bit PIC microcontroller, the PIC18F67K40 from Microchip, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a mikroProg connector, and two 26-pin headers for interfacing with external electronics. Its compact design with clear and easily recognizable silkscreen markings allows you to build gadgets with unique functionalities and features quickly.
Each part of the Clicker 2 for PIC18FK development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the Clicker 2 for PIC18FK programming method: using UART mikroBootloader, an external mikroProg connector for PIC18FK programmer, or through Xpress bootloader, the Clicker 2 board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Micro-B cable, where onboard voltage regulators provide the appropriate voltage levels to each component
on the board, or using a Li-Polymer battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several user-configurable buttons and LED indicators. Clicker 2 for PIC18FK is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping 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
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
64
RAM (Bytes)
3562
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 Clicker 2 for PIC18FK 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 Magneto 9 Click driver.
Key functions:
magneto9_read_adc_voltage- This function reads raw 12-bit ADC data and converts it to voltage by using I2C serial interfacemagneto9_read_an_pin_voltage- This function reads results of AD conversion of the AN pin and converts them to proportional voltage levelmagneto9_get_pwm_pin- This function returns the PWM pin logic state.
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 Magneto 9 Click Example.
*
* # Description
* This example demonstrates the use of Magneto 9 Click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and logger.
*
* ## Application Task
* Reads the ADC voltage and calculates the magnetic field strength from it.
* Voltage increases with increasing positive (south) applied magnetic field.
* All data are being displayed on the USB UART where you can track their changes.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "magneto9.h"
static magneto9_t magneto9; /**< Magneto 9 Click driver object. */
static log_t logger; /**< Logger object. */
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
magneto9_cfg_t magneto9_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 );
Delay_ms ( 100 );
log_info( &logger, " Application Init " );
// Click initialization.
magneto9_cfg_setup( &magneto9_cfg );
MAGNETO9_MAP_MIKROBUS( magneto9_cfg, MIKROBUS_1 );
if ( ADC_ERROR == magneto9_init( &magneto9, &magneto9_cfg ) )
{
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float voltage = 0;
if ( MAGNETO9_OK == magneto9_read_an_pin_voltage ( &magneto9, &voltage ) )
{
float field_strength = MAGNETO9_VOLTAGE_TO_FIELD_STRENGTH ( voltage );
log_printf( &logger, " ADC Voltage : %.3f V\r\n", voltage );
log_printf( &logger, " Magnetic field strength : %.3f mT\r\n", field_strength );
if ( field_strength < 0 )
{
log_printf( &logger, " The North Pole magnetic field prevails.\r\n\n" );
}
else
{
log_printf( &logger, " The South Pole magnetic field prevails.\r\n\n" );
}
}
Delay_ms ( 1000 );
}
int main ( void )
{
/* Do not remove this line or clock might not be set correctly. */
#ifdef PREINIT_SUPPORTED
preinit();
#endif
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
