Ensure ideal temperature and humidity conditions for your well-being using HDC2010 and PIC18F4515

The secret to ideal living!

Published Nov 07, 2023

Click board™

Temp&Hum 3 click

Dev Board

EasyPIC v7

Compiler

NECTO Studio

MCU

PIC18F4515

Experience effortless comfort with our solution that maintains the perfect temperature and humidity levels

Hardware Overview

How does it work?

Temp&Hum 3 Click is based on the HDC2010, a low-power humidity and temperature digital sensor from Texas Instruments. This sensor is factory calibrated to 2% relative humidity and 0.2°C temperature accuracy. It has an integrated heating element that is used to evaporate condensation, protecting the sensor that way. 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 power consumption might rise to about 130mA. Internally, two sensors are connected to the ADC section, which can be set to sample measurements with the resolution of 9, 11 or 14 bits, based on the measurement time. 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 HDC2010 datasheet so that the final temperature or relative humidity data can be

calculated. It is also possible to correct the offsets with custom values. HDC2010 IC 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 ADDR pin of the HDC2010 is routed to the CS pin of the mikroBUS™ and it represents the least significant bit of the I2C address. The final I2C address of this IC is determined by setting this pin either to a HIGH logic level for 1, or a LOW logic level for 0. Temp&Hum 3 click supports programmable interrupt engine, saving the host MCU from having to constantly poll the IC for data. An interrupt signal with a selectable polarity and behavior can be generated on the DRDY/INT pin of the HDC2010. It can be triggered by several event sources: it can be triggered by the temperature Lo/Hi threshold events, Humidity Lo/Hi events, as well as the readiness status of the measurement data. Setting up the interrupts can be

achieved by programming the appropriate IC registers via the I2C bus. More information about these registers can be found in the HDC2010 datasheet. HDC2010 IC itself is a very low power consuming device and it can work in two modes: sleep and active (measurement) mode. The device enters the sleep the mode as soon possible, to save power. While in the active mode, measurement can be either automatic with predefined output data rate (ODR) or on-demand. In the automatic mode, the measurement is triggered in predefined time segments, while on-demand measurement happens whenever the I2C command is sent. As soon as the single measurement is finished, the device falls back to a sleep mode. Onboard SMD jumper is used to select the power supply voltage. This allows Temp&Hum 3 click to be used with both 3.3V and 5V MCUs.

Temp&Hum 3 click hardware overview image

Features overview

Development board

EasyPIC v7 is the seventh generation of PIC development boards specially designed to develop embedded applications rapidly. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB-B. 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, EasyPIC v7 allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of

the EasyPIC 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 various 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-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. These sockets cover a wide range of 8-bit PIC MCUs, from PIC10F, PIC12F, PIC16F, PIC16Enh, PIC18F, PIC18FJ, and PIC18FK families. EasyPIC 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

PIC

MCU Memory (KB)

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

3968

Used MCU Pins

mikroBUS™ mapper

RST

I2C Address Selection

RE0

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM

Interrupt

RB0

INT

I2C Clock

RC3

SCL

I2C Data

RC4

SDA

Power Supply

Ground

GND

Take a closer look

Schematic

Step by step

Project assembly

EasyPIC v7 front image hardware assembly

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

EasyPIC 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

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 Temp&Hum 3 Click driver.

Key functions:

temphum3_get_temperature - Get temperature value
temphum3_get_huminidy - Get temperature value
temphum3_get_max_hum - Get maximum temperature value

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 TempHum3 Click example
 * 
 * # Description
 * This application reads temperature and humidity data.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes Driver init and settings chip mode ACTIVE and configuration Measurement and Interrupt, 
 * then settings maximum / minimum possible Temperature and Huminidy.
 * 
 * ## Application Task  
 * Reads the temperature and huminidy and logs to the USBUART every 500 ms.
 * 
 * 
 * \author Petar Suknjaja
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "temphum3.h"

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

static temphum3_t temphum3;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    temphum3_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.

    temphum3_cfg_setup( &cfg );
    TEMPHUM3_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    temphum3_init( &temphum3, &cfg );
    log_info( &logger, "---- Init done -----" );
    
    temphum3_default_cfg( &temphum3 );
    
    log_info( &logger, "--- Settings Temp&Hum done---" );
}

void application_task ( void )
{
    float temperature;
    float humidity;

    //  Task implementation.
    
    temperature = temphum3_get_temperature( &temphum3 );
    log_printf( &logger, " Temperature : %f C \r\n", temperature );
    
    humidity = temphum3_get_humidity( &temphum3 );
    log_printf( &logger, " Humidity : %f %% \r\n", humidity );
    Delay_ms( 500 );
}

void main ( void )
{
    application_init( );

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


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