Air Flow Click

How does it work?

Air Flow Click as its foundation uses the LHDULTRAM012UB3, an LHD ULTRA series flow-based 2-in-1 differential pressure sensor from TE Connectivity Measurement Specialties. It consists of two combined calorimetric micro-flow channels and two sensor elements on a single chip. The first sensing element ensures precise measurement of low differential pressures with high resolution, and the second sensing element is optimized for pressures in the upper measuring range. A fast-response 24-bit onboard controller delivers precise measurement results across the entire dynamic measuring range from 0 to 1250Pa.

The specific concept of the LHDULTRAM012UB3 ensures continuous operation that is highly reliable and economically efficient in addition to the outstanding long-term stability, precision with patented real-time offset compensation, and linearization techniques. The LHD ULTRA’s high flow impedance ensures product-specific insensitivity to dust/moisture as well as minimal flow leakage.

Air Flow Click provides the possibility of using both I2C and SPI interfaces with a maximum frequency of 100kHz for I2C and 1MHz for SPI communication. The selection can be made by positioning SMD jumpers labeled as COMM SEL to an appropriate position. Note that all the jumpers’ positions must be on the same side, or else the Click board™ may become unresponsive.

While the I2C interface is selected, the LHDULTRAM012UB3 allows the choice of the least significant bit (LSB) of its I2C slave address using the SMD jumpers labeled as A0 and A1 to an appropriate position marked as 0 and 1. Also, an additional ready signal, routed on the INT pin of the mikroBUS™ socket, is added, indicating that new data is ready for the host.

This 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

Pinout diagram

This table shows how the pinout on Air Flow Click 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	RDY	Data Ready
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
SPI Data OUT	SDO	5	MISO	SCL	12	SCL	I2C Clock
SPI Data IN	SDI	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

Air Flow Click electrical specifications

Software Support

We provide a library for the Air Flow Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Air Flow Click driver.

Key functions:

• airflow_cfg_setup – Config Object Initialization function.
• airflow_init – Initialization function.
• airflow_default_cfg – Click Default Configuration function.

Examples description

This example showcases ability for device to read differential pressure, atmospheric pressure and ambient temperature.

The demo application is composed of two sections :

void application_task ( void ) 
{    
    float pressure_data, temperature_data;
    
    airflow_get_differential_pressure( &airflow, &pressure_data );
    log_printf( &logger, "Differential pressure[Pa]: %.2frn", pressure_data );
    airflow_get_atmospheric_pressure( &airflow, &pressure_data, &temperature_data );
    log_printf( &logger, "Atmospheric pressure[mBar]: %.2frnTemperature[degC]: %.2frn", pressure_data, temperature_data );
    log_printf( &logger, "***********************************************************rn" );
    Delay_ms( 500 );
}

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.AirFlow

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 click or RS232 click 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

This 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.

For more information about mikroSDK, visit the official page.