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Embrace a smarter and more convenient way of life with HTU21DF and STM32F756ZG

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Temp&Hum 13 Click with UNI Clicker

Published Nov 08, 2023

Click board™

Temp&Hum 13 Click

Development board

UNI Clicker

Compiler

NECTO Studio

MCU

STM32F756ZG

Take control of your surroundings and make data-driven decisions for maximum comfort and productivity.

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Hardware Overview

How does it work?

Temp&Hum 13 Click is based on the HTU21DF, a digital relative humidity sensor with temperature output from TE Connectivity. This sensor is factory calibrated to ±2% relative humidity and ±0.3°C temperature accuracy. It has an integrated heating element that is used for functionality diagnosis as well. This heating element can be simply activated by setting a bit in the appropriate register. In the case when the heater is powered on, the typical power consumption is about 5.5mW. Internally, two sensors are connected to the two separated ADC sections with variable resolution of 12 -14 bits for the temperature and 8-12 bits for relative humiditiy measurement. The OTP memory holds the calibration coefficients that are applied to the measured value and the results are stored on the output registers, in the MSB/LSB format. These values are then used in formulas found in the HTU21DF datasheet so that the final temperature or relative humidity data can be

calculated. It is also possible to correct the offsets with custom values. Temp&Hum 13 click uses the I2C protocol to communicate with the host MCU. Its I2C bus pins are routed to the mikroBUS™ I2C pins and are pulled to a HIGH logic level by the onboard resistors. The final I2C address of this IC is factory determined. There are two different operation modes to communicate with the HTU21D sensor: Hold Master mode and No Hold Master mode. In the first case, the SCK line is blocked (controlled by HTU21D(F) sensor) during measurement process while in the second case the SCK line remain open for other communication while the sensor is processing the measurement. The HTU21DF IC itself is a very low power consumption device and it can work in two modes: sleep and active (measurement) mode. The device enters the sleep the mode as soon as possible, to save power. This makes the HTU21DF suitable to be used in battery-powered applications. In these

applications, the HTU21DF spends most of the time in sleep mode, with the typical current consumption of 20 nA. While in the active mode, the typical current consumption is 450µA. The provided Click board™ library contains simple and easy to use functions, which simplify configuring and reading of the measurement data. These functions are demonstrated in the included example application and can be used as a reference for custom projects. These functions can be used in mikroC, mikroBasic and mikroPascal compilers for all MCU architectures, supported by MikroElektronika. This Click Board™ is designed to be operated only with 3.3V logic level. A proper logic voltage level conversion should be performed before the Click board™ is used with MCUs with logic levels of 5V. It is ready to be used as soon as it is inserted into a mikroBUS™ socket of the development system.

Temp&Hum 13 Click hardware overview image

Features overview

Development board

UNI Clicker is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It supports a wide range of microcontrollers, such as different ARM, PIC32, dsPIC, PIC, and AVR from various vendors like Microchip, ST, NXP, and TI (regardless of their number of pins), four mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a debugger/programmer connector, and two 26-pin headers for interfacing with external electronics. Thanks to innovative manufacturing technology, it allows you to build

gadgets with unique functionalities and features quickly. Each part of the UNI Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the UNI Clicker programming method, using a third-party programmer or CODEGRIP/mikroProg connected to onboard JTAG/SWD header, the UNI Clicker board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Type-C (USB-C) connector, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or using a Li-Po/Li

Ion battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board (plus USB HOST/DEVICE), including the well-established mikroBUS™ socket, a standardized socket for the MCU card (SiBRAIN standard), and several user-configurable buttons and LED indicators. UNI Clicker 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.

UNI clicker double image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

ARM Cortex-M7

MCU Memory (KB)

1024

Silicon Vendor

STMicroelectronics

Pin count

144

RAM (Bytes)

327680

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB8
SCL
I2C Data
PB9
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

Temp&Hum 13 Click Schematic schematic

Step by step

Project assembly

UNI Clicker front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI Clicker as your development board.

UNI Clicker front image hardware assembly
Thermo 28 Click front image hardware assembly
SiBRAIN for STM32F745VG front image hardware assembly
Prog-cut hardware assembly
UNI Clicker MB 1 - upright/with-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
Necto image step 7 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

After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.

Application Output Step 1

After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.

Application Output Step 3

Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.

Application Output Step 4

Software Support

Library Description

This library contains API for Temp&Hum 13 Click driver.

Key functions:

  • temphum13_get_humidity - This function calculates humidity.

  • temphum13_get_temperature -This function calculates current temperature.

  • temphum13_change_resolution - This function sets click measurement resolution.

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 
 * \brief TempHum13 Click example
 * 
 * # Description
 * This demo shows basic TempHum13 click functionality - temperature
 * and humidity measurement. 
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initialize device.
 * 
 * ## Application Task  
 * Measure temperature and humidity values on every 0,5 seconds,
 * and log them to UART Terminal if they are valid.
 * 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "temphum13.h"

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

static temphum13_t temphum13;
static log_t logger;

static float temperature;
static float humidity;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    temphum13_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.

    temphum13_cfg_setup( &cfg );
        Delay_ms(500);
    TEMPHUM13_MAP_MIKROBUS( cfg, MIKROBUS_1 );
        Delay_ms(500);
    temphum13_init( &temphum13, &cfg );
        Delay_ms(500);
    
    temphum13_default_cfg( &temphum13 );
}

void application_task ( void )
{
    temperature = temphum13_get_temperature( &temphum13 );
    humidity = temphum13_get_humidity( &temphum13 );
    
    if ( temperature != 65536.0 )
    {
        log_printf( &logger, "\r\n> Temperature : %.2f C", temperature );
    }

    if ( humidity != 65536.0 )
    {       
        log_printf( &logger, "\r\n> Humidity    : %.2f%%RH\r\n", humidity );
    } 

    Delay_ms( 500 );
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources