The ASDX sensor of Honeywell exist in many variations. Check the datasheet of your type for all the details. The I2C_ASDX library can read the sensor and give the pressure in millibar, bar or PSI or ...
The library gives control over up to 16 parallel working PIR devices over I2C. The idea for this library came up in a discussion about how to fully cover an area with PIR sensors without blind spots ...