Make your thermal monitor using STS31-DIS and PIC18F86J55

Your temperature experts!

Published Feb 17, 2023

Click board™

Thermo 26 Click

Dev Board

UNI-DS v8

Compiler

NECTO Studio

MCU

PIC18F86J55

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

UNI-DS 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 STM32, Kinetis, TIVA, CEC, MSP, PIC, dsPIC, PIC32, and AVR MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. 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, UNI-DS v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the UNI-DS 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. UNI-DS 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

PIC

MCU Memory (KB)

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

3904

Used MCU Pins

mikroBUS™ mapper

Reset

PJ4

RST

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM

Alert Interrupt

PB0

INT

I2C Clock

PC3

SCL

I2C Data

PC4

SDA

Power Supply

Ground

GND

Take a closer look

Schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI-DS v8 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.

Buck 22 Click front image hardware assembly

SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly

v8 SiBRAIN MB 1 - upright/background hardware assembly

NECTO Compiler Selection Step Image hardware assembly

Track your results in real time

Application Output

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

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

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

/*!
 * @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