Intermediate
30 min
0

Unveil pressure's secrets with LPS33HW and TM4C1294KCPDT

High-tech sensing: Digital pressure measurement in focus

Pressure 11 Click with Fusion for Tiva v8

Published Oct 13, 2023

Click board™

Pressure 11 Click

Development board

Fusion for Tiva v8

Compiler

NECTO Studio

MCU

TM4C1294KCPDT

Precision meets simplicity with our digital pressure measurement solution, making complex measurements accessible and accurate for professionals in any field

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Hardware Overview

How does it work?

Pressure 11 Click is based on the LPS33HW, an absolute digital output barometer IC in water-resistant package from STMicroelectronics. It can be used to measure absolute pressure values from 260 - 1260hPa. The sensor can be exposed up to 2MPa of pressure peaks, without causing any permanent damage. However, prolonged exposure to such high pressure can affect the reliability and accuracy of the sensor. The LPS33HW IC comprises a piezoresistive MEMS and an ASIC. The MEMS consists of a suspended membrane manufactured using a proprietary technology, developed by ST. The piezoresistive elements on the membrane form a Wheatstone bridge. By applying a pressure, the balance of the bridge is disturbed, which causes a proportional voltage to appear on its output. The output of the Wheatstone bridge is then processed by the ASIC, which outputs conditioned and factory-calibrated data over the SPI or I2C interface, in 24-bit, two’s complement format. Pressure 11 click supports both SPI and I2C communication interfaces, allowing it to be used with a wide range of different MCUs. The communication interface can be chosen by moving SMD jumpers grouped

under the COM SEL to an appropriate position (SPI or I2C). The slave I2C address can also be configured by a SMD jumper, when the Click board™ is operated in the I2C mode: a SMD jumper labeled as ADD SEL is used to set the least significant bit (LSB) of the I2C address. When set to 1, the 7-bit I2C slave address becomes 0b1011101x. If set to 0, the address becomes 0b1011100x. The last digit (x) is the R/W bit. One of distinctive features of the LPS33HW is a highly configurable FIFO buffer, with 32 slots of 40-bit data, allowing to buffer both pressure and temperature readings. The FIFO buffer can be configured to work in one of several available modes, offering a great flexibility. Along with the extensive interrupt engine which can signal several FIFO-related events over a dedicated INT_DRDY pin, the FIFO buffer can be very useful for writing an optimized MCU firmware. Besides FIFO-related events, the extensive interrupt engine of the LPS33HW IC can be configured to signal several other events over a dedicated INT_DRDY pin, including events when a programmable low or high threshold level is exceeded, and events when there is a data ready to be read from the output. The INT_DRDY pin of

the LPS33HW IC is routed to the mikroBUS™ INT pin. Its active state (active LOW or active HIGH) is freely configurable. Pressure data at the output is in 24-bit, two’s complement format. Thanks to the highly advanced ASIC, the output is already formatted in physical units, with minimum operations required from the host MCU. Since the sensitivity is 4096 LSB/hPa, the output result should be divided by 4096 in order to obtain the value in hPa units. Temperature data is in 16-bit two’s complement format, and it does not require any conversions. The sensitivity of the temperature sensor is 100 LSB/⁰C so the output result should be divided by 100 in order to obtain the value in ⁰C units. ASIC also offers some other processing functions such as the lowpass filtering of the output data, which helps reducing the inconsistencies due to sudden pressure changes. This Click Board™ uses both I2C and SPI communication interfaces. It is designed to be operated only with 3.3V logic levels. A proper logic voltage level conversion should be performed before the Click board™ is used with MCUs with logic levels of 5V.

Pressure 11 Click top side image
Pressure 11 Click bottom side image

Features overview

Development board

Fusion for TIVA v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different 32-bit ARM® Cortex®-M based MCUs from Texas Instruments, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over a WiFi network. 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. Thanks to innovative manufacturing technology, Fusion for TIVA v8 provides a fluid and immersive working experience, allowing access

anywhere and under any circumstances at any time. Each part of the Fusion for TIVA v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.

Communication options such as USB-UART, USB HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. Fusion for TIVA v8 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.

Fusion for Tiva v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

ARM Cortex-M4

MCU Memory (KB)

512

Silicon Vendor

Texas Instruments

Pin count

128

RAM (Bytes)

262144

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
SPI Chip Select
PH0
CS
SPI Clock
PQ0
SCK
SPI Data OUT
PQ3
MISO
SPI Data IN
PQ2
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
PQ4
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PD2
SCL
I2C Data
PD3
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

Pressure 11 Click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Fusion for Tiva v8 as your development board.

Fusion for PIC v8 front image hardware assembly
Buck 22 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
v8 SiBRAIN 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 Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image 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.

UART Application Output Step 1

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.

UART Application Output Step 2

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".

UART Application Output Step 3

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.

UART Application Output Step 4

Software Support

Library Description

This library contains API for Pressure 11 Click driver.

Key functions:

  • pressure11_check_id - Functions for cheking commuincation with the chip and checking its ID

  • pressure11_get_temperature - Functions for temperature reading

  • pressure11_get_pressure - Functions for pressure reading

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 Pressure11 Click example
 * 
 * # Description
 * This sensor offers many benefits, including low power consumption,
 *  high resolution of the pressure data, embedded thermal compensation,
 *  FIFO buffer with several operating modes, temperature measurement, etc.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes SPI driver and checks chip ID
 * 
 * ## Application Task  
 * Reads Pressure and Temperature values and displays it on UART LOG
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "pressure11.h"

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

static pressure11_t pressure11;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    pressure11_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.

    pressure11_cfg_setup( &cfg );
    PRESSURE11_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    pressure11_init( &pressure11, &cfg );
    
    uint8_t id_flag =  pressure11_check_id( &pressure11 );
    if ( DEVICE_ERROR == id_flag )
    {
        log_info( &logger, "---- Error Comm ----" );
        for( ; ; );
    }
    Delay_ms( 500 );
}

void application_task ( void )
{
    float temperature;
    float pressure;
        
    temperature = pressure11_get_temperature( &pressure11 );
    log_printf( &logger, "Temperature: %.2f degC\r\n", temperature );
 
    pressure = pressure11_get_pressure( &pressure11 );
    log_printf( &logger, "Pressure:  %.2f hPa (mBar)\r\n", pressure );
    log_printf( &logger, "-------------------------------------------------\r\n" );
 
    Delay_ms( 500 );
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources