Reach new heights with MPL3115A2 and STM32F091RC
Measure height relative to sea level or ground level
Published Feb 26, 2024
Click board™
Altitude Click
Dev. board
Nucleo-64 with STM32F091RC MCU
Compiler
NECTO Studio
MCU
STM32F091RC
Provide accurate measurements of the current altitude or elevation of an object or location with high resolution and reliability
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Hardware Overview
How does it work?
Altitude Click is based on the MPL3115A2, a low-power, high-accuracy digital output altimeter, barometer, and thermometer from NXP Semiconductors. A high-resolution 24-bit ADC digitizes the MPL3115A2 outputs; it provides 20-bit pressure/altitude and 12-bit temperature data with an altitude resolution of 30cm. Pressure output can be resolved with output in fractions of a Pascal and altitude in fractions of a meter. The high stability of both pressure and temperature signals makes it suitable for accurate altimetry in various applications. The MPL3115A2 contains automatic internal data processing with data acquisition and compensation, which removes compensation tasks from the host MCU, and a 32-sample FIFO buffer to minimize the overhead of collecting multiple data
samples. Numerous user-programmable, power-saving, and interrupt modes are available, including programmed acquisition cycle timing and poll-only modes. It can also autonomously collect data at programmed intervals and store it for up to 12 days, depending on the data acquisition rate (1 second - 9 hours). This Click board™ communicates with MCU using the standard I2C 2-Wire interface with a maximum clock frequency of 400kHz. The MPL3115A2 also features two independently programmable interrupt signals, IT1 and IT2, routed to the INT and CS pins on the mikroBUS™ socket, entirely programmed by the user through the I2C interface (functions, threshold, and the timing of the interrupt pins). These can be set to generate an interrupt signal when a new set
of pressure/altitude and temperature data is available, simplifying data acquisition for the host MCU. It can also be configured to generate interrupts when a user-programmed set of conditions are met, such as when a single new data acquisition is ready, when a desired number of samples are stored within the internal FIFO, or when a change of pressure/altitude or temperature is detected. This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ 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
Nucleo-64 with STM32F091RC MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M0
MCU Memory (KB)
256
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
32768
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo-64 with STM32F091RC MCU as your development board.
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 Altitude Click driver.
Key functions:
altitude_generic_single_write- Generic Single Write functionaltitude_generic_multiple_read- Generic Multiple Read functionaltitude_get_altitude- Altitude Get function
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 Altitude Click example
*
* # Description
* This is a example which demonstrates the use of Altitude Click board.
* This demo example offers the altitude [m], pressure [mbar] and temperature
* [deg C] measurements from sensor.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes I2C driver and all used pins, performs a default configuration
* for Altitude Click board and initializes the uart console for results
* logging.
*
* ## Application Task
* Shows two different uses of sensor, altimeter and barometer mode.
* Reads the altitude, pressure and temperature results in standard units and
* sends this results to the console.
*
* \author Nemanja Medakovic
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "altitude.h"
// ------------------------------------------------------------------ VARIABLES
static altitude_t altitude;
static log_t console;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init( void )
{
altitude_cfg_t altitude_cfg;
log_cfg_t log_cfg;
// Click initialization.
altitude_cfg_setup( &altitude_cfg );
ALTITUDE_MAP_MIKROBUS( altitude_cfg, MIKROBUS_1 );
altitude_init( &altitude, &altitude_cfg );
altitude_default_cfg( &altitude );
/**
* 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( &console, &log_cfg );
log_printf( &console, "*** Altitude initialization done ***\r\n" );
log_printf( &console, "**************************************\r\n" );
}
void application_task( void )
{
float altitude_result;
float pressure_result;
float temperature_result;
// Altimeter sensor mode for altitude data reading.
altitude_set_sensor_mode( &altitude, ALTITUDE_SENSMOD_ALTIMETER );
Delay_ms( 100 );
while ( 0 == altitude_get_drdy_status( &altitude, ALTITUDE_STATUS_FLAG_PDR ) );
altitude_result = altitude_get_altitude( &altitude );
// Barometer sensor mode for pressure data reading.
altitude_set_sensor_mode( &altitude, ALTITUDE_SENSMOD_BAROMETER );
Delay_ms( 100 );
while ( 0 == altitude_get_drdy_status( &altitude, ALTITUDE_STATUS_FLAG_PDR ) );
pressure_result = altitude_get_pressure( &altitude );
temperature_result = altitude_get_temperature( &altitude );
log_printf( &console, "** Altitude is %.2f m\r\n", altitude_result );
log_printf( &console, "** Pressure is %.2f mbar\r\n", pressure_result );
log_printf( &console, "** Temperature is %.2f Celsius\r\n", temperature_result );
log_printf( &console, "**************************************\r\n" );
}
void main( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
