Pressure 21 Click is a compact add-on board that contains a board-mount pressure sensor. This board features the BMP581, an absolute barometric pressure sensor from Bosch Sensortec. The BMP581 provides a relative accuracy of ±6Pa and typical absolute accuracy of ±30Pa with ultra-low noise, low power consumption, and temperature stability alongside programmable output: temperature-only or both pressure and temperature (pressure-only is not supported). It converts output data into a 24-bit digital value and sends the information via a configurable host interface that supports SPI and I2C serial communications. It measures pressure from 30kPa up to 125kPa over a wide operating temperature range. This Click board™ is suited for various pressure-based applications, industrial, consumer, weather stations, and more.

Pressure 21 Click as its foundation uses the BMP581, a high accuracy, low power, barometric pressure, and temperature sensor solution from Bosch Sensortec. The BMP581 provides proper absolute pressure and temperature measurements, due to on-chip linearization and temperature compensation, from 30kPa to 125kPa over a wide operating temperature range from -40 to +85°C. It also provides a relative accuracy of ±6Pa and typical absolute accuracy of ±30Pa with ultra-low noise, low power consumption, and temperature stability alongside programmable output: temperature-only or both pressure and temperature (pressure-only is not supported).

The BMP581 operates in three power modes: Sleep, Normal, and Forced Mode. The Normal Mode comprises automated perpetual cycling between an active measurement period and an inactive Standby period. In Sleep Mode, no measurements are being performed, while in Forced Mode, a single measurement performs. When a measurement is finished, the BMP581 returns to Sleep Mode. Also, a set of oversampling settings are available, ranging from ultra-low power to highest resolution setting to adapt the Click board™ to the target application.

Pressure 21 Click allows using both I2C and SPI interfaces with a maximum frequency of 1MHz for I2C and 10MHz for SPI communication. The selection can be made by positioning SMD jumpers labeled as COMM SEL in an appropriate position. Note that all the jumpers' positions must be on the same side, or the Click board™ may become unresponsive. While the I2C interface is selected, the BMP581 allows choosing the least significant bit (LSB) of its I2C peripheral address using the SMD jumper labeled ADDR SEL. This Click board™ also possesses an additional interrupt pin, routed to the INT pin on the mikroBUS™ socket, indicating when a specific interrupt event occurs, such as FIFO overflow, the threshold over/underrun, data-ready, and more.

This Click board™ can be operated only 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.

• Interface: I²C, SPI
• Compatibility: mikroBUS™
• Dimensions: 28.6 x 25.4mm
• Input Voltage: 3.3V
• Supply Voltage: 3.3V
• Pressure Measurement Range: Min. 30 kPa, Max. 125 kPa
• Relative Pressure Accuracy: ±6 Pa
• Absolute Pressure Accuracy: ±30 Pa
• Resolution: 24 bit
• Operating Temperature Range: Min. -40°C, Typ. +25°C, Max. +85°C

• Schematic
• BMP581 Datasheet
• mikroSDK
• LibStock