Beginner
10 min

Ensure your space remains cozy and balanced with Si7034 and PIC32MZ2048EFM100

Measure the elements that matter most for a healthier environment

Temp&Hum 2 Click with Curiosity PIC32 MZ EF

Published Nov 07, 2023

Click board™

Temp&Hum 2 Click

Dev Board

Curiosity PIC32 MZ EF

Compiler

NECTO Studio

MCU

PIC32MZ2048EFM100

Our mission is to empower you with precise temperature and humidity measurements, ensuring that you can effortlessly maintain a balanced, comfortable, and eco-conscious living or working space

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Hardware Overview

How does it work?

Temp&Hum 2 Click is based on the Si7034, a digital humidity and temperature sensor IC with I2C interface, from Silicon Labs. It is a digital relative humidity and a temperature sensor that integrates temperature and humidity sensor elements, an analog-to-digital converter, signal processing, calibration, and data correction on the chip. Each chip is factory calibrated, and the calibration data is stored in its non-volatile memory. The maximum accuracy achieved with this sensor is ± 4% RH for the humidity range from 0 to 80%. Besides the humidity sensing element, this sensor includes an accurate thermal sensor, which can achieve up to ±0.4 °C. It is used in conjunction with the humidity measurement, to allow thermal compensation of the relative humidity measurements. This sensor IC also has an integrated heating element that is used to evaporate condensation reducing the effect of the offset accumulation when used in high humidity conditions, or to implement dew-point

measurement when the Si7034 is used with a separate temperature sensor. The heating element current can be adjusted by the appropriate bits in the Humidity Control Register. Due to the nature of the used sensors, a special care should be taken to reduce the sensor contamination to a minimum. Particles, dirt or other artifacts collected on the surface of the exposed polymer film will affect its ability to measure the humidity, and therefore, the manufacturer recommends protecting the sensor against particles. The sensor otherwise has a long aging period with minimal drift. Synthetic long-term stability tests show less than 0.25 %RH per year drift. The data provided by the IC is ready to be used directly. Two measurements are done when a command is received via the I2C. One is the humidity measurement, while the second is temperature measurement, used for the compensation. Si7034 IC operates on 1.8V and therefore, a small LDO has to be used to convert 3.3V from the mikroBUS™

power rail, down to 1.8V. In addition, the I2C signal voltage levels also have to be converted so it can be used with the MCUs operated with 3.3V. For this purpose, the Click board™ utilizes the PCA9306, a level shifting IC, made by Texas Instruments. It uses 1.8V as the first reference voltage and 3,3V from the mikroBUS™ power rail as the second reference voltage, shifting the I2C communication signal levels, allowing this Click board™ to be used with MCUs operated at 3.3V. The sensor IC is physically located away from other components on the Click board™, so the heating influence of the surrounding components or PCB is reduced to a minimum, allowing the accuracy of the Click board™ to stay within the specifications. The i2C lines of the IC are routed to the mikroBUS™ and supplied by the pull-up resistors, allowing this Click board™ to be used right out of the box. Temp&Hum 2 click uses only 3.3V rail from the mikroBUS™.

Temp&Hum 2 Click hardware overview 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

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
RPA14
SCL
I2C Data
RPA15
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

Temp&Hum 2 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
Thermo 28 Click front image hardware assembly
Prog-cut hardware assembly
Curiosity PIC32 MZ EF MB 1 - 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

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 2 Click driver.

Key functions:

  • temhum2_get_eletronic_id - This function for reads Eletronic ID

  • temphum2_set_mode - Functions for set measurement mode

  • temphum2_get_measurement - Functions for mesurement

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 TempHum2 Click example
 * 
 * # Description
 * This application measures temperature and humidity. 
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes driver init, set work mode and Heater
 * 
 * ## Application Task  
 * Reads temperature and humidity and logs values on usbuart for every 500ms.
 * 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "temphum2.h"

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

static temphum2_t temphum2;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    temphum2_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.

    temphum2_cfg_setup( &cfg );
    TEMPHUM2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    temphum2_init( &temphum2, &cfg );

    temphum2_default_cfg( &temphum2 );
}

void application_task ( void )
{
    float data_buffer[ 2 ];
    
    temphum2_get_measurement( &temphum2, &data_buffer[ 0 ] );
    
    log_printf( &logger, " --- Temperature : %.2f C \r\n ", data_buffer[ 0 ] );
    log_printf( &logger, " --- Humidity : %.2f RH \r\n ", data_buffer[ 1 ] );
    
    Delay_ms( 500 );
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources