VAV Press Click Board™

Product Code: MIKROE-4667

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 -