With our digital sensors, you can monitor and control pressure variations in real time, ensuring safety and precision in your applications
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Hardware Overview
How does it work?
Pressure 5 Click is based on the BMP388, a digital pressure sensor, from Bosch Sensortec. This sensor consists of a piezo-resistive pressure sensing element and a mixed-signal ASIC which performs A/D conversions and provides the conversion results through a digital interface. This advanced MEMS technology offers a high measurement precision of 0.08hPa, as well as low TOC (thermal coefficient) of only 0.75 Pa/K. The sensor is enclosed in a small metal lid housing and is highly resilient: it can operate in a range of 300 hPa to 1250 hPa but can withstand up to 20,000 hPa before the membrane breaks down. The BMP388 offers a set of pressure and temperature measurement options. It can be programmed to skip either thermal or pressure measurement, allowing faster measurement of the required property. The low TOC of only 0.75Pa/K allows reading of the pressure with very small drift over temperature. Resolution of 0.08hPa allows calculating of the altitude with the accuracy of about 66 cm, which is ideal for indoor navigation applications (drones, flying toy models, and similar). The IIR filter is especially useful for indoor usage, allowing filtering of some short-term disturbances, such as slamming doors or windows. FIFO buffer allows for an optimization of the host firmware, reducing the data traffic through the
communication interface. It has 512 bytes and it is backed up by an interrupt engine, which can trigger an interrupt event when the buffer is full, or when the watermark level is reached. Also, the behavior of the FIFO buffer can be programmed to either skip new data once it is full or to overwrite the oldest data. The interrupt is available over the INT pin, and can be used to further optimize the host firmware (i.e. to reduce the power consumption by utilizing the INT pin to wake up the host MCU). Besides FIFO events, the INT pin also signals when there is a new data available at the output register (Data Ready event). This sensor consists of a mixed signal front-end (ASIC) and a piezo-sensitive pressure sensing element. The ASIC contains a low-noise 24-bit A/D converter, along with the digital signal processing section. The measurement data is available either over the I2C or the SPI interface. Pressure 5 click offers a choice between these two interfaces. The selection can be done by positioning SMD jumpers labeled as COMM SEL to an appropriate position. Note that all the jumpers must be placed to the same side, else the Click board™ may become unresponsive. While the I2C interface is selected, the BMP388 allows the choice of the least significant bit (LSB) of its I2C slave address. This can be done by using the SMD jumper
labeled as ADDR SEL. The overall power consumption depends on several factors, such as the oversampling value, measurement rate, power mode, standby duration, and so on. Bosh Sensortech recommends a set of operational parameters for different applications, in the form of a table, in the BMP388 datasheet. In general, this sensor allows several power modes, regardless of the selected measurement parameters. When the measurement is completed, raw ADC values will be available in the output registers. However, to obtain actual pressure and temperature readings, a compensation algorithm needs to be applied. A set of compensation parameters is available in the non-volatile memory of the BMP388 device. These compensation parameters take into account slight differences between the produced samples and each BMP388 device has its own set of parameters. The BMP388 datasheet offers detailed instructions on how to apply these compensating algorithms properly. However, MikroElektronika provides a library with functions which can be used for a simplified and thus faster application development. The library also contains a demo example, which demonstrates the use of these functions. The demo application can be used as a reference for a custom design.
Features overview
Development board
UNI-DS 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 STM32, Kinetis, TIVA, CEC, MSP, PIC, dsPIC, PIC32, and AVR MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. 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, UNI-DS v8 provides a fluid and immersive working experience, allowing access anywhere and under any
circumstances at any time. Each part of the UNI-DS 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. UNI-DS 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.
Microcontroller Overview
MCU Card / MCU
Type
8th Generation
Architecture
dsPIC
MCU Memory (KB)
256
Silicon Vendor
Microchip
Pin count
100
RAM (Bytes)
16384
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project 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 5 Click driver.
Key functions:
pressure5_update_coefficient
- This function allows you to update the calibration coefficientpressure5_get_temperature_data
- This function gets temperature in Celsiuspressure5_get_pressure_data
- This function gets pressure in mBar
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 Pressure5 Click example
*
* # Description
* This example preforms Temperature and Pressure measurement.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization driver init, test comunication, software reset, update
* coefficient and configuration module for start measurement.
*
* ## Application Task
* Reads Pressure data in [mBar] and Temperature data in [C].
* Logs all data to the USBUART every 2 seconds.
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "pressure5.h"
// ------------------------------------------------------------------ VARIABLES
static pressure5_t pressure5;
static log_t logger;
static float temperature;
static float pressure;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
pressure5_cfg_t cfg;
PRESSURE5_RETVAL init_ret;
/**
* 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.
pressure5_cfg_setup( &cfg );
PRESSURE5_MAP_MIKROBUS( cfg, MIKROBUS_1 );
pressure5_init( &pressure5, &cfg );
pressure5_default_cfg( &pressure5 );
}
void application_task ( void )
{
// Task implementation.
temperature = pressure5_get_temperature_data ( &pressure5 );
log_printf( &logger, "Temperature: %.2f C\r\n", temperature );
pressure = pressure5_get_pressure_data ( &pressure5 );
log_printf( &logger, "Pressure: %.2f mBar\r\n ", pressure );
log_printf( &logger, "\r\n" );
Delay_ms( 1000 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END