Monitor atmospheric pressure smoothly with ILPS22QS and PIC18F57Q43

The science behind barometer readings: Understanding pressure and weather changes

Barometer 8 Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

Barometer 8 Click

Dev Board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Provide insights into the scientific concepts underpinning barometer measurements and their relationship with weather patterns

Hardware Overview

How does it work?

Barometer 8 Click is based on the ILPS22QS, a high-accuracy absolute pressure sensor that functions as a digital output barometer from STMicroelectronics. The ILPS22QS delivers ultra-low pressure noise with low power consumption and operates over an extended temperature range. It has a selectable dual full-scale absolute pressure range, from 260 up to 1260hPa or 4060hPa, with an accuracy of 0.5hPa, ideally suited to the harsh environmental conditions in industrial and consumer applications. The ILPS22QS comprises a sensing element based on a piezoresistive Wheatstone bridge approach and an IC interface that provides a digital signal from

the sensing element to the application. The sensing element, which detects absolute pressure, consists of a suspended membrane manufactured using a dedicated process developed by ST. A silicon spring structure surrounds this silicon membrane, contributing to isolating the membrane from mechanical and thermal stress in applications. When pressure is applied, the membrane deflection induces an imbalance in the Wheatstone bridge piezoresistance, whose output signal is converted by the selected interface. This Click board™ allows the use of both I2C and SPI interfaces with a maximum frequency of 1MHz for I2C and 8MHz for SPI communication. The

selection can be made by positioning SMD jumpers labeled COMM SEL to an appropriate position. Note that all the jumpers' positions must be on the same side, or the Click board™ may become unresponsive. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Features overview

Development board

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.

PIC18F57Q43 Curiosity Nano double side image

Microcontroller Overview

MCU Card / MCU

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

8196

You complete me!

Accessories

Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.

Used MCU Pins

mikroBUS™ mapper

RST

SPI Chip Select

PD4

SPI Clock

PC6

SCK

SPI Data OUT

PC5

MISO

SPI Data IN

PC4

MOSI

Power Supply

3.3V

Ground

GND

PWM

INT

I2C Clock

PB2

SCL

I2C Data

PB1

SDA

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

Curiosity Nano Base for Click boards front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.

Charger 27 Click front image hardware assembly

PIC18F47Q10 Curiosity Nano front image hardware assembly

Curiosity Nano with PICXXX Access MB 1 - upright/background hardware assembly

PIC18F57Q43 Curiosity MCU Step hardware assembly

Necto No Display image step 8 hardware assembly

Debug Image 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 Barometer 8 Click driver.

Key functions:

barometer8_write_register - This function writes a desired data byte to the selected register
barometer8_read_register - This function reads a data byte from the selected register
barometer8_read_data - This function reads the pressure and temperature raw data and converts them to mBar and Celsius

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 Barometer8 Click example
 *
 * # Description
 * This example demonstrates the use of Barometer 8 click board by reading and
 * displaying the pressure and temperature values.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs the click default configuration.
 *
 * ## Application Task
 * Reads and displays the pressure and temperature data on the USB UART every 250ms approximately,
 * as per output data rate (ODR) bits configuration.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "barometer8.h"

static barometer8_t barometer8;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    barometer8_cfg_t barometer8_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.
    barometer8_cfg_setup( &barometer8_cfg );
    BAROMETER8_MAP_MIKROBUS( barometer8_cfg, MIKROBUS_1 );
    err_t init_flag  = barometer8_init( &barometer8, &barometer8_cfg );
    if ( ( I2C_MASTER_ERROR == init_flag ) || ( SPI_MASTER_ERROR == init_flag ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( BAROMETER8_ERROR == barometer8_default_cfg ( &barometer8 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    float pressure, temperature;
    if ( BAROMETER8_OK == barometer8_read_data ( &barometer8, &pressure, &temperature ) )
    {
        log_printf ( &logger, " Pressure: %.1f mBar\r\n", pressure );
        log_printf ( &logger, " Temperature: %.2f C\r\n\n", temperature );
    }
    Delay_ms( 5 );
}

void main ( void )
{
    application_init( );

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

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