






How Does The VAV Press Click Board™ Work?
The VAV Press Click Board™ is based on the LMIS025B, a low differential pressure sensor that offers a digital output for reading pressure over the specified pressure span from First Sensor (part of TE Connectivity). The innovative LMI technology features superior sensitivity, especially for ultra-low pressures ranging from 0 to 25Pa / 0 to 0.25mbar (0.1 in H2O). It is based on thermal flow measurement of gas through a micro-flow channel integrated within the sensor chip.
The extremely low gas flow through the sensor ensures high immunity to dust contamination, humidity, and long tubing compared to other flow-based pressure sensors, in addition to the outstanding long-term stability, precision with patented real-time offset compensation, and linearization techniques.
The LMIS025B offers two modes of operation: Continuous mode with a 5ms sampling time which provides a near-continuous stream of pressure data, and low-power mode with a 400μA Standby current which wakes the device from Sleep to serve pressure data "on-demand". The first measurement in either mode is available after a warm-up and conversion sequence, which takes approximately 25 ms.
The VAV Press Click Board™ communicates with MCU using the standard I2C 2-Wire interface offering linearized digital output through a 16-bit sigma-delta A/D conversion. Besides, it also allows the choice of the least significant bit of its I2C slave address by positioning the SMD jumper labelled as ADDR SEL to an appropriate position marked as 0 and 1.
The VAV Press Click Board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before use with 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.
SPECIFICATIONS
Type | Pressure |
Applications | Can be used for pressure measurements in automotive applications, industrial and consumer applications |
On-board modules | LMIS025B - low differential pressure sensor that offers a digital output for reading pressure over the specified pressure span from First Sensor (part of TE Connectivity). |
Key Features | Low power consumption, ultra-low pressure ranges, based on thermal microflow measurement, high flow impedance, outstanding long-term stability, on-chip temperature sensor, two modes of oprerations, and more |
Interface | I2C |
Compatibility | mikroBUS |
Click board size | M (42.9 x 25.4 mm) |
Input Voltage | 3.3V |
PINOUT DIAGRAM
This table shows how the pinout of the VAV Press Click Board™ corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).
Notes | Pin | ![]() |
Pin | Notes | |||
---|---|---|---|---|---|---|---|
NC | 1 | AN | PWM | 16 | NC | ||
NC | 2 | RST | INT | 15 | NC | ||
NC | 3 | CS | RX | 14 | NC | ||
NC | 4 | SCK | TX | 13 | NC | ||
NC | 5 | MISO | SCL | 12 | SCL | I2C Clock | |
NC | 6 | MOSI | SDA | 11 | SDA | I2C Data | |
Power Supply | 3.3V | 7 | 3.3V | 5V | 10 | NC | |
Ground | GND | 8 | GND | GND | 9 | GND | Ground |
ONBOARD SETTINGS AND INDICATORS
Label | Name | Default | Description |
---|---|---|---|
LD1 | PWR | - | Power LED Indicator |
JP1-JP2 | ADDR SEL | Left | I2C Address Selection 0/1: Left position 0, Right position 1 |
VAV PRESS CLICK ELECTRICAL SPECIFICATIONS
Description | Min | Typ | Max | Unit |
---|---|---|---|---|
Supply Voltage | - | 3.3 | - | V |
Pressure Measurement Range | 0 | - | 0.25 | mbar |
Accuracy | - | 0.5 | - | % |
Operating Temperature Range | -40 | +25 | +85 | °C |
Software Support
We provide a library for the VAV Press Click Board™ as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.
The package can be downloaded/installed directly from NECTO Studio The package Manager (recommended), downloaded from our LibStock™ or found on mikroE Github account.
Library Description
This library contains API for the VAV Press Click Board™ driver.
Key Functions
vavpress_cfg_setup
- Config Object Initialization function.vavpress_init
- Initialization function.vavpress_default_cfg
- Click Default Configuration function.
Example Description
This library contains API for the VAV Press Click Board™ driver. This demo application shows an example of differential pressure and temperature measurement.
void application_task ( void ) { err_t error_flag = vavpress_get_dif_press_and_temp( &vavpress, ¶m_data, &diff_press, &temperature ); if ( error_flag == VAVPRESS_OK ) { log_printf( &logger, " Diff. Pressure : %.4f Parn", diff_press ); log_printf( &logger, " Temperature : %.4f Crn", temperature ); log_printf( &logger, "--------------------------------rn" ); Delay_ms( 2000 ); } else { log_error( &logger, " Communcation Error. " ); log_info( &logger, " Please, run program again... " ); for ( ; ; ); } }
The full application code, and ready to use projects can be installed directly from NECTO Studio The package Manager (recommended), downloaded from our LibStock™ or found on mikroE Github account.
Other mikroE Libraries used in the example:
- MikroSDK.Board
- MikroSDK.Log
- Click.VavPress
Additional Notes and Information
Depending on the development board you are using, you may need USB UART Click Board™, USB UART 2 Click Board™ or RS232 Click Board™ to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.
MIKROSDK
The VAV Press Click Board™ is supported with mikroSDK - MikroElektronika Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.
VAV Press Click Board
Frequently Asked Questions
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