Make your thermal monitor using STS31-DIS and PIC18F97J60

Your temperature experts!

Published Feb 20, 2023

Click board™

Thermo 26 Click

Dev. board

PICPLC16 v7a

Compiler

NECTO Studio

MCU

PIC18F97J60

Undoubtedly the best choice for highly accurate temperature measurements

Hardware Overview

How does it work?

Thermo 26 Click is based on the STS31-DIS, a digital temperature sensor from Sensirion with increased intelligence, reliability, NIST traceability, and improved accuracy specifications utilizing the industry-proven CMOSens® Technology. It integrates a digital temperature sensor with a 16-bit analog-to-digital converter (ADC), a data processing circuit, and serial interface logic functions in one package. The voltage is digitized and converted to a 16-bit temperature result in degrees Celsius, with a resolution of 0.01°C. The STS31-DIS temperature sensor gives a fully calibrated, linearized, and supply-voltage-

compensated digital output with outstanding accuracy of up to ±0.2°C typical over a temperature range of 0°C to 90°C. Thermo 26 Click communicates with an MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting Fast Mode Plus up to 1MHz. Also, the STS31-DIS allows choosing the least significant bit (LSB) of its I2C slave address using the SMD jumper labeled ADDR SEL. It also possesses an additional interrupt alert signal, routed on the INT pin of the mikroBUS™ socket labeled as ALT. The ALT pin indicates when a specific

interrupt event occurs, depending on the temperature reading value relative to programmable limits. The general reset function is routed on the RST pin of the mikroBUS™ socket. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

Features overview

Development board

PICPLC16 v7a is the seventh generation of PIC development boards, providing an environment for experimenting with industrial devices. It comes with an onboard 8-bit PIC microcontroller, the PIC18F97J60 from Microchip, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over USB-C. The development board also consists of 16 opto-inputs and 16 relays for currents up to 16A. It is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, and connectors, in one place. With eight connectors for each port, PICPLC16 v7a

allows you to develop PIC-based industrial, home, or office automation applications more efficiently than ever. Each part of the PICPLC16 v7a development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board 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, 7-23V AC or 9-32V DC via DC connector/screw terminals, and a power source via the USB Type-C (USB-C) connector. Communication options such as LIN and Ethernet are also included, alongside the well-established mikroBUS™ standard. PICPLC16 v7a is an integral part of the Mikroe ecosystem for rapid industrial 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

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

3808

Used MCU Pins

mikroBUS™ mapper

Reset

RG6

RST

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM

Alert Interrupt

RB0

INT

I2C Clock

RC3

SCL

I2C Data

RC4

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

PICPLC16 v7a front image hardware assembly

Start by selecting your development board and Click board™. Begin with the PICPLC16 v7a as your development board.

Buck 22 Click front image hardware assembly

PICPLC16 v7a MB 1 - upright/background hardware assembly

NECTO Compiler Selection Step Image hardware assembly

Necto_MCU_Select_PICPLC16 hardware assembly

Necto No Display image step 8 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 Thermo 26 Click driver.

Key functions:

thermo26_read_serial_num This function reads the 32-bit unique serial number.
thermo26_start_measurement This function starts the measurements by sending the specified command.
thermo26_read_temperature This function reads the temperature raw data measurements and converts them to degrees Celsius.

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 Thermo 26 Click example
 *
 * # Description
 * This example demonstrates the use of Thermo 26 click board by reading and displaying
 * the temperature measurements.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and resets the device, and after that reads the serial number and
 * starts the periodic measurements at 2 mps with high repeatability.
 *
 * ## Application Task
 * Reads the temperature measurement in degrees Celsius and displays the results on the USB UART
 * approximately once per second.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "thermo26.h"

static thermo26_t thermo26;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    thermo26_cfg_t thermo26_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.
    thermo26_cfg_setup( &thermo26_cfg );
    THERMO26_MAP_MIKROBUS( thermo26_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == thermo26_init( &thermo26, &thermo26_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    thermo26_reset_device ( &thermo26 );
    
    uint32_t serial_num;
    if ( THERMO26_ERROR == thermo26_read_serial_num ( &thermo26, &serial_num ) )
    {
        log_error( &logger, " Read serial number." );
        for ( ; ; );
    }
    log_printf ( &logger, " Serial number: 0x%.8LX\r\n", serial_num );
    
    if ( THERMO26_ERROR == thermo26_start_measurement ( &thermo26, THERMO26_CMD_PERIODIC_2_MPS_REP_HIGH ) )
    {
        log_error( &logger, " Start measurement." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    float temperature;
    if ( THERMO26_OK == thermo26_read_temperature ( &thermo26, &temperature ) )
    {
        log_printf ( &logger, " Temperature: %.2f\r\n\n", temperature );
    }
    Delay_ms ( 1000 );
}

void main ( void ) 
{
    application_init( );

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

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