Provide reliable temperature measurements with STS40-AD1B and ATmega644P

Experience unmatched temperature control

Published Apr 05, 2023

Click board™

Thermo 24 Click

Dev. board

EasyAVR v7

Compiler

NECTO Studio

MCU

ATmega644P

Keep your environment at the perfect temperature with our state-of-the-art temperature solution

Hardware Overview

How does it work?

Thermo 24 Click is based on the STS40-AD1B, a high-accuracy ultra-low-power 16-bit temperature sensor from Sensirion. This temperature sensor is characterized by high accuracy; a temperature range of -40°C to +120°C provides typical ±0.2°C accuracy. 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 STS40-AD1B achieves the most

significant cost efficiency among comparable sensors. The STS40-AD1B communicates with MCU using a standard I2C 2-Wire interface. Given that this chip can be found in multiple versions with its unique I2C slave address, this version, specifically the STS40-AD1B, comes with the slave address of 0x44. Since the sensor for operation requires a 3.3V logic voltage level only, this Click board™ also features the PCA9306 voltage-level translator from Texas Instruments. The I2C interface bus lines are routed to the dual bidirectional voltage-level translator, allowing this Click board™

to work properly with 3.3V and 5V MCUs. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VIO 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

EasyAVR v7 is the seventh generation of AVR development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 16-bit AVR microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB. The development board is well organized and designed so that the end-user has all the necessary elements in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyAVR v7 allows you to connect accessory boards, sensors, and custom electronics more

efficiently than ever. Each part of the EasyAVR v7 development board contains the components necessary for the most efficient operation of the same board. An integrated mikroProg, a fast USB 2.0 programmer with mikroICD hardware In-Circuit Debugger, offers many valuable programming/debugging options and seamless integration with the Mikroe software environment. Besides it 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, 7-12V AC or 9-15V DC via DC connector/screw terminals, and a power source via the USB Type-B (USB-B)

connector. Communication options such as USB-UART and RS-232 are also included, alongside the well-established mikroBUS™ standard, three display options (7-segment, graphical, and character-based LCD), and several different DIP sockets which cover a wide range of 16-bit AVR MCUs. EasyAVR v7 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

Architecture

AVR

MCU Memory (KB)

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

4096

Used MCU Pins

mikroBUS™ mapper

RST

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM

INT

I2C Clock

PC0

SCL

I2C Data

PC1

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

EasyAVR v7 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyAVR v7 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

EasyAVR v7 MB 1 - upright/background hardware assembly

NECTO Compiler Selection Step Image hardware assembly

Necto DIP image step 7 hardware assembly

EasyPIC PRO v7a Display Selection 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 Thermo 24 Click driver.

Key functions:

thermo24_soft_reset This function performs the software reset by sending the soft reset command by using I2C serial interface.
thermo24_read_serial This function reads the 4-byte chip serial number using I2C serial interface.
thermo24_read_temperature This function reads the temperature in Celsius with the specified measurement precision.

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 Thermo24 Click example
 *
 * # Description
 * This example demonstrates the use of Thermo 24 Click board by reading and displaying
 * the temperature measurements.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and logger, then performs the software reset of the Click board 
 * and reads and displays its serial number.
 *
 * ## Application Task
 * Reads the temperature measurement in Celsius and displays the results on the USB UART
 * approximately once per second.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "thermo24.h"

static thermo24_t thermo24;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    thermo24_cfg_t thermo24_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.
    thermo24_cfg_setup( &thermo24_cfg );
    THERMO24_MAP_MIKROBUS( thermo24_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == thermo24_init( &thermo24, &thermo24_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( THERMO24_ERROR == thermo24_soft_reset ( &thermo24 ) )
    {
        log_error( &logger, " Software reset." );
        for ( ; ; );
    }

    uint32_t serial_num;
    if ( THERMO24_OK == thermo24_read_serial ( &thermo24, &serial_num ) )
    {
        log_printf ( &logger, " Serial Number: 0x%.8LX\r\n", serial_num );
    }
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    float temperature;
    if ( THERMO24_OK == thermo24_read_temperature ( &thermo24, THERMO24_MEASURE_PRECISION_HIGH, &temperature ) )
    {
        log_printf ( &logger, " Temperature: %.2f C\r\n\n", temperature );
        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