Experience a new era of climate monitoring convenience with BPS240 and PIC18F87J50

Safeguard your health and well-being with in-depth weather monitoring

Published Nov 09, 2023

Click board™

Temp&Hum 19 Click

Dev Board

EasyPIC PRO v7a

Compiler

NECTO Studio

MCU

PIC18F87J50

Optimize various processes by closely monitoring temperature and humidity, minimizing risks and enhancing product quality.

Hardware Overview

How does it work?

Temp&Hum 19 Click is based on the BPS240, relative humidity, and temperature sensor from Bourns. The BPS240 is based on innovative MEMS technology, which provides highly accurate condition readings. The humidity can be measured within a range of 0 to 100 %RH, while the temperature sensor is designed for a range of -30 to +100 °C. The enhanced features include a faster response time of less than one second with digital output and higher accuracy, with a typical RH accuracy of 2% in the measuring range of 20 up to 80 %RH at ambient temperature and ±0.3 °C for its operating temperature range with low

power consumption. Temp&Hum 19 Click communicates with MCU using the standard I2C 2-Wire interface to read data supporting Standard Mode operation with a clock frequency up to 100kHz, providing 10-bit data to the host controller. The output data is processed and compensated by the BPS240 sensor itself, requiring only basic conversion formulas to be applied within the firmware of the host controller. These conversion formulas are given in the BPS240 datasheet and directly provide readings in °C and %RH. This Click board™ also possesses an enabling function. The Enable pin is labeled as EN and routed to the

PWM pin of the mikroBUS™ socket, which activates and powers up the BPS240 (used for power ON/OFF purposes) and thus enables optimized power consumption. 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. Also, this 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.

Temp&Hum 19 Click hardware overview image

Features overview

Development board

EasyPIC PRO v7a 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 a broad set of unique functions, such as the first-ever embedded debugger/programmer over USB-C. 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. With two different connectors for each port, EasyPIC PRO v7a allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of the EasyPIC PRO

v7a development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board 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, 7-23V AC or 9-32V DC via DC connector/screw terminals, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART,

RS-232, and Ethernet are also included, including the well-established mikroBUS™ standard, two display options (graphical and character-based LCD), and a standard TQFP socket for the seventh-generation MCU cards. This socket covers a wide range of 8-bit PIC MCUs, from PIC18LF, PIC16LF, PIC16F, and PIC18F families. EasyPIC PRO v7a 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

7th Generation

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

3904

Used MCU Pins

mikroBUS™ mapper

RST

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

Enable

RC1

PWM

INT

I2C Clock

RC3

SCL

I2C Data

RC4

SDA

Power Supply

Ground

GND

Take a closer look

Schematic

Step by step

Project assembly

EasyPIC PRO v7a front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC PRO v7a 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 PRO v7 MCUcard with PIC18F87J50 front image hardware assembly

v7 TQFP 3SOC MB 1 - upright/background hardware assembly

NECTO Compiler Selection Step Image hardware assembly

EasyPIC PRO v7a MCU Selection Necto Step 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 19 Click driver.

Key functions:

temphum19_restart_chip - This function restarts the chip by toggling the EN pin state.
temphum19_set_mode_reg - This function programs the mode register with a desired mode value, and stores it to the ctx->detection_mode variable.
temphum19_read_data - This function reads temperature and humidity raw data and converts them to Celsius and Percents respectfully.

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 TempHum19 Click example
 *
 * # Description
 * This example demonstrates the use of Temp & Hum 19 click board by reading
 * the temperature and humidity data.
 * 
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs the click default configuration.
 *
 * ## Application Task
 * Reads the temperature (Celsius) and humidity (Percents) data and displays the
 * results on the USB UART approximately once per second.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "temphum19.h"

static temphum19_t temphum19;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    temphum19_cfg_t temphum19_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.
    temphum19_cfg_setup( &temphum19_cfg );
    TEMPHUM19_MAP_MIKROBUS( temphum19_cfg, MIKROBUS_1 );
    
    if ( I2C_MASTER_ERROR == temphum19_init( &temphum19, &temphum19_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( TEMPHUM19_ERROR == temphum19_default_cfg ( &temphum19 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    float temperature, humidity;
    if ( TEMPHUM19_OK == temphum19_read_data ( &temphum19, &temperature, &humidity ) ) 
    {
        log_printf ( &logger, " Temperature: %.1f C\r\n", temperature );
        log_printf ( &logger, " Humidity: %.2f %%\r\n\n", humidity );
        Delay_ms ( 1000 );
    }
}

void main ( void ) 
{
    application_init( );

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

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