Stay on top of temperature fluctuations with BH1900NUX and STM32F091RC
The temperature solution you can trust
Published Feb 26, 2024
Click board™
Thermo 13 Click
Dev. board
Nucleo-64 with STM32F091RC MCU
Compiler
NECTO Studio
MCU
STM32F091RC
Discover how our temperature measurement solution can help you address temperature challenges and enhance your competitive edge
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Hardware Overview
How does it work?
Thermo 13 Click is based on the BH1900NUX, a high accuracy temperature sensor IC with the 2-Wire interface, from ROHM Semiconductor. The Click board™ itself has a reasonably small number of components because most of the measurement circuitry is already integrated on the BH1900NUX sensor. The I2C compatible serial interface lines, along with the INT pin, which also works in the open drain configuration, are pulled up by the onboard resistors. The 2-Wire lines are routed to the respective I2C lines of the mikroBUS™ (SCK and SDA), while the ALERT pin of the sensor IC is routed to the INT pin of the mikroBUS™. The sensor IC uses the I2C compatible communication interface. There are five registers, used to set the high and low temperature limits, temperature hysteresis for the interrupt events, configuration register used to store all the working parameters, read-only register which holds the sampled temperature data, and more. More information about all the registers can be found in the BH1900NUX datasheet. However, provided library contains functions that simplify the use of the Thermo 13 click. The included application example demonstrates their functionality and it can be used as a reference for custom design. An analog signal from the thermal sensor is sampled by the internal ADC converter. Thanks to high
resolution ADC, the step size can be as small as 0.0625°C. The INT pin is used to trigger an interrupt event on the host MCU. This pin has a programmable polarity: it can be set to be asserted either to a HIGH logic level or to a LOW logic level by setting POL bit in the configuration register. Since the Click board™ features a pull-up resistor, it is advised to set the polarity so that the asserted state drives the pin to a LOW logic level. A special mechanism is employed to reduce false ALERT triggering. This mechanism includes queueing of the cycles in which the temperature limit is exceeded The ALERT pin can be set to work in two different modes: Comparator mode and thermostat mode. When working in the Comparator mode, this pin will be triggered whenever a temperature limit is exceeded. The INT pin stays asserted until the temperature drops below the hysteresis level. Both values are set in the respective temperature registers (limit and hysteresis). This mode is useful for thermostat-like applications: it can be used to power down a system in case of overheating or turn off the cooling fan if the temperature is low enough. If set to work in the thermostat mode, the INT pin will stay asserted when the temperature exceeds the value in the high limit register. When the temperature drops below the hysteresis level, the INT pin will be cleared. This mode is
used to trigger an interrupt on the host MCU, which is supposed to read the sensor when the interrupt event is generated. The device can be set to work in several different power modes. It can be set to continuously sample the temperature measurements, it can be set to the shutdown mode. The shutdown mode consumes the least power, keeping all the internal sections but the communication section, unpowered. This allows for a lower power consumption. The design of the Click board™ itself is such that the thermal radiation from other components, which might affect the environmental temperature readings of the sensor, is reduced. The onboard SMD jumper labeled as VCC SEL allows voltage selection for interfacing with both 3.3V and 5V MCUs. Thermo 13 click supports I2C communication interface, allowing it to be used with a wide range of different MCUs. The slave I2C address can be configured by an SMD jumpers, labeled as A0, A1 and A2. They are used to set the last three bis of the I2C address. This Click Board™ is designed to be operated only with up to 3.3V logic levels. Proper conversion of logic voltage levels should be applied, before the Click board™ is used with MCUs operated at 5V.
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 Thermo 13 Click driver.
Key functions:
thermo13_set_temp_limit- Set temperature limit registerthermo13_get_temp_limit- Get temperature registerthermo13_get_ambient_temperature_data- Ambient temperature data
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
* \brief Thermo13 Click example
*
* # Description
* The application measures temperature
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver init, configures the module and
* reads the temperature Limit LOW/HIGH values that are set.
*
* ## Application Task
* Reads ambient temperature data and this data logs to USBUART every 1500ms.
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "thermo13.h"
// ------------------------------------------------------------------ VARIABLES
static thermo13_t thermo13;
static log_t logger;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
thermo13_cfg_t cfg;
float temp_limit_low;
float temp_limit_high;
/**
* 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
thermo13_cfg_setup( &cfg );
THERMO13_MAP_MIKROBUS( cfg, MIKROBUS_1 );
thermo13_init( &thermo13, &cfg );
// Configuration
thermo13_configuration( &thermo13, THERMO13_CFG_CONTINUOUS_MEASUREMENT |
THERMO13_CFG_FAULT_QUEUE_1 |
THERMO13_CFG_ALERT_ACTIVE_HIGH |
THERMO13_CFG_INTERRUPT_IS_ACTIVE |
THERMO13_CFG_WAIT_TIME_X16 );
// Temperature Register
log_printf( &logger, " --- Temperature register data --- \r\n \r\n" );
temp_limit_low = thermo13_get_temp_limit ( &thermo13, THERMO13_REG_TEMPERATURE_LIMIT_LOW );
log_printf( &logger, " --- Temp - Limit LOW : %.2f C \r\n ", temp_limit_low );
temp_limit_high = thermo13_get_temp_limit ( &thermo13, THERMO13_REG_TEMPERATURE_LIMIT_HIGH );
log_printf( &logger, " --- Temp - Limit HIGH : %.2f C \r\n \r\n ", temp_limit_high );
log_printf( &logger, " --- Ambient temperature measurement --- \r\n " );
}
void application_task ( void )
{
float temperature;
temperature = thermo13_get_ambient_temperature_data ( &thermo13, THERMO13_TEMP_IN_CELSIUS );
log_printf( &logger, "** temperature %.2f ** \r\n", temperature );
log_printf( &logger, " ----------------------------\r\n" );
Delay_ms ( 1500 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
