Beginner
10 min

Achieve unmatched accuracy and reliability in temperature measurement with MAX31865 and PIC32MZ2048EFM100

Your partner for ultra-precise temperature monitoring!

RTD Click with Curiosity PIC32 MZ EF

Published Nov 07, 2023

Click board™

RTD Click

Dev. board

Curiosity PIC32 MZ EF

Compiler

NECTO Studio

MCU

PIC32MZ2048EFM100

Mastery of temperature control begins with our RTD solution, meticulously crafted for PT100 platinum probes, setting a new benchmark in precision.

A

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Hardware Overview

How does it work?

RTD Click is based on the MAX31865, a resistance to digital converter from Analog Devices, optimized for platinum resistance temperature detectors, or RTD. The click uses the PT100 type platinum probe for temperature measurement. There are four screw terminals on the board, so different PT100 probe types can be used with this design. This click board™ can work with 2, 3 or 4-wire PT100 probe types. RTD probes are

commonly used to measure a range of temperatures between −200°C and 500°C, but the exact value depends on the specific probes used. Features like the 15bit ADC resolution, input terminals overvoltage protection up to ±45V, fault detection, a fast response time of 21mS and the SPI interface, make the RTD click an ideal solution when it comes to the precise measuring of extremely high and low temperatures. 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.

RTD Click top side image
RTD Click bottom side image

Features overview

Development board

Curiosity PIC32 MZ EF development board is a fully integrated 32-bit development platform featuring the high-performance PIC32MZ EF Series (PIC32MZ2048EFM) that has a 2MB Flash, 512KB RAM, integrated FPU, Crypto accelerator, and excellent connectivity options. It includes an integrated programmer and debugger, requiring no additional hardware. Users can expand

functionality through MIKROE mikroBUS™ Click™ adapter boards, add Ethernet connectivity with the Microchip PHY daughter board, add WiFi connectivity capability using the Microchip expansions boards, and add audio input and output capability with Microchip audio daughter boards. These boards are fully integrated into PIC32’s powerful software framework, MPLAB Harmony,

which provides a flexible and modular interface to application development a rich set of inter-operable software stacks (TCP-IP, USB), and easy-to-use features. The Curiosity PIC32 MZ EF development board offers expansion capabilities making it an excellent choice for a rapid prototyping board in Connectivity, IOT, and general-purpose applications.

Curiosity PIC32MZ EF double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

524288

You complete me!

Accessories

The PT100 3-wire temperature probe is an advanced RTD platinum sensor designed for precise temperature measurement up to 250°C. Perfectly compatible with the RTD Click board™, this probe utilizes RTD sensors - thermosensitive resistors that adapt their resistance to temperature changes. The probe's core features a meticulously crafted strip of platinum with a resistance of 100Ω at 0°C, earning the designation PT100. Key features include a temperature range of up to 250⁰ Celsius, a 3-wire configuration for enhanced accuracy, a length of 1m (100cm, 3.37 inches), Grade 2B construction for durability, and a tight tolerance of 0.5". Whether in industrial or scientific settings, the PT100 3-wire temperature probe delivers reliable and precise temperature readings, ensuring optimal performance in diverse applications.

RTD Click accessories image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
SPI Chip Select
RPD4
CS
SPI Slock
RPD1
SCK
SPI Data OUT
RPD14
MISO
SPI Data IN
RPD3
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Data-Ready
RF13
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

RTD Click Schematic schematic

Step by step

Project assembly

Curiosity PIC32MZ EF front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity PIC32 MZ EF as your development board.

Curiosity PIC32MZ EF front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
Curiosity PIC32 MZ EF MB 1 Access - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Curiosity PIC32 MZ EF MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image 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 RTD Click driver.

Key functions:

  • rtd_read_register - This function reads data from the chosen register.

  • rtd_read_temperature - This function reads data from temperature registers.

  • rtd_convert_temperature - This function convert data from temperature registers.

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 Rtd Click example
 * 
 * # Description
 * This app measures temperature and converts the data to celsius degrees.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes RTD click driver, and sets the
 * proper configuration mode for three wire RTD.
 * 
 * ## Application Task  
 * Measures temperature, converts the data to celsius degrees,
 * and displays it on the USB UART.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "rtd.h"

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

static rtd_t rtd;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    rtd_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.
    rtd_cfg_setup( &cfg );
    RTD_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    rtd_init( &rtd, &cfg );
    
    RTD_SET_DATA_SAMPLE_EDGE;

    rtd_write_register( &rtd, RTD_CONFIGURATION, 0xD0 );
    Delay_ms ( 100 );
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    uint16_t read_value = 0;
    float converted_value = 0;

    read_value = rtd_read_temperature( &rtd );
    converted_value = rtd_convert_temperature( &rtd, read_value, RTD_REF_RESISTANCE_470 );

    log_printf( &logger, " Current temperature: %.2f \r\n", converted_value );

    Delay_ms ( 300 );
}

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
/*!
 * \file 
 * \brief Rtd Click example
 * 
 * # Description
 * This app measures temperature and converts the data to celsius degrees.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes RTD click driver, and sets the
 * proper configuration mode for three wire RTD.
 * 
 * ## Application Task  
 * Measures temperature, converts the data to celsius degrees,
 * and displays it on the USB UART.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "rtd.h"

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

static rtd_t rtd;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    rtd_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.
    rtd_cfg_setup( &cfg );
    RTD_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    rtd_init( &rtd, &cfg );
    
    RTD_SET_DATA_SAMPLE_EDGE;

    rtd_write_register( &rtd, RTD_CONFIGURATION, 0xD0 );
    Delay_ms ( 100 );
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    uint16_t read_value = 0;
    float converted_value = 0;

    read_value = rtd_read_temperature( &rtd );
    converted_value = rtd_convert_temperature( &rtd, read_value, RTD_REF_RESISTANCE_470 );

    log_printf( &logger, " Current temperature: %.2f \r\n", converted_value );

    Delay_ms ( 300 );
}

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

Additional Support

Resources

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