Access real-time, reliable pressure data with DPS310 and PIC18F26K40

Measure the world's pulse: Digital barometric sensor at your service!

Published Nov 01, 2023

Click board™

Pressure 3 Click

Dev Board

EasyPIC v7a

Compiler

NECTO Studio

MCU

PIC18F26K40

Navigate the world of meteorology and beyond with confidence, thanks to our advanced digital barometric sensor engineered for accuracy and versatility

Hardware Overview

How does it work?

Pressure 3 Click is based on the DPS310, a digital barometric pressure sensor from Infineon. This miniaturized sensor, with high accuracy and low power consumption, is capable of measuring not only the pressure but temperature as well in a range of -40 up to 85°C with a half-degree accuracy. Its sensing element is based on a capacitance sensing principle, so it achieves high precision during temperature changes. Each unit for measuring pressure and temperature is individually calibrated, and the internal signal processor converts the outputs to a 24-bit result. The calibration coefficients, stored in registers, convert measurements to high-accuracy values, both for pressure and temperature. The DPS310 integrates a FIFO (First-In-First-Out) buffer that can store the last 32 measurements, which can save power as the host MCU doesn’t have to poll

for results constantly. The DPS310 operates in three operating modes. In Standby mode, as a default mode, no measurements are performed. It is a mode after the Power-on or reset conditions in which all registers and coefficients are accessible. In Command mode (manual), the DPS310 performs one temperature and pressure measurement, after which the sensor returns to Standby mode. The measurement results are available in the data registers. In Background mode (automatic), pressure and/or temperature measurements are continuously performed according to the selected precision and rate. The DPS310 will first perform a pressure measurement and, after that, the temperature measurement. To communicate with the host MCU, the Pressure 3 Click offers a choice between two interfaces, the I2C and the SPI. The selection can be made by

positioning the SMD jumpers labeled SPI I2C to an appropriate position (I2C selected by default). Note that all the jumpers must be placed on the same side, or the Click board™ may become unresponsive. The interrupt function is available over the INT pin only while using this Click board™ via an I2C interface and can be triggered whenever a new measurement is available or if a FIFO buffer is full. 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

EasyPIC v7a is the seventh generation of PIC development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has 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 in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyPIC v7a allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of the EasyPIC 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 module 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-C (USB-C) 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 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

Architecture

PIC

MCU Memory (KB)

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

3728

Used MCU Pins

mikroBUS™ mapper

RST

SPI Chip Select

RA5

SPI Clock

RC3

SCK

SPI Data OUT

RC4

MISO

SPI Data IN

RC5

MOSI

Power Supply

3.3V

Ground

GND

PWM

Interrupt

RB1

INT

I2C Clock

RC3

SCL

I2C Data

RC4

SDA

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

EasyPIC v7a front image hardware assembly

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

Rotary B 2 Click front image hardware assembly

EasyPIC v7a MB 2 - 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 via UART Mode

1. Once the code example is loaded, pressing the "FLASH" button initiates the build process, and programs it on the created setup.

2. After the programming is completed, click on the Tools icon in the upper-right panel, and select the UART Terminal.

3. After opening the UART Terminal tab, first check the baud rate setting in the Options menu (default is 115200). If this parameter is correct, activate the terminal by clicking the "CONNECT" button.

4. Now 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 Pressure 3 Click driver.

Key functions:

pressure3_get_t_p_data - Get temperature pressure
pressure3_get_coefficients - Get coefficients
pressure3_get_measurement_data - Read the coefficients value for calculation function

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 Pressure3 Click example
 * 
 * # Description
 * This application is digital barometric pressure sensor.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initialization device, set default configuration and start to write log.
 * 
 * ## Application Task  
 * This is an example which demonstrates the use of Pressure 3 Click board.
     Measured pressure and temperature data from the DPS310 sensor on Pressure 3 click board.
     Results are being sent to the Usart Terminal where you can track their changes.
     All data logs write on usb uart changes for every 3 sec.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "pressure3.h"

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

static pressure3_t pressure3;
static log_t logger;

static pressure3_coeff_t coeff_struct;

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

void application_init ( )
{
    log_cfg_t log_cfg;
    pressure3_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.

    pressure3_cfg_setup( &cfg );
    PRESSURE3_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    pressure3_init( &pressure3, &cfg );
    pressure3_default_cfg( &pressure3 );
}

void application_task ( )
{
    float pressure;
    float temperature;

    pressure3_get_t_p_data( &pressure3, &temperature, &pressure, &coeff_struct );
    
    log_printf( &logger, " * Pressure: %.2f mbar * \r\n", pressure );
    log_printf( &logger, " * Temperature: %.2f C * \r\n", temperature );
    log_printf( &logger, " ----------------------- \r\n" );

    Delay_ms( 3000 );
}

void main ( )
{
    application_init( );

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

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