Sometimes you need to sense pressure in a damp or caustic environment. And sometimes you need to know the relative changes in pressure as well as the absolute pressure. For the times you need to do both (or either), the LPS33HW is the pressure sensor for you. Combining protection from water intrusion with support for high precision relative and absolute measurements, this sensor will do what you need. With drivers for CircuitPython, Arduino, and Raspberry Pi, and support for I2C or SPI (Arduino only SPI support, for now) you'll be measuring pressure in any situation in no time.

According to ST, the LPS33HW is designed for and proven to protect electronic components from long-term exposure to harsh environments such as water mixed with chlorine, bromine, commercial washing detergent and fuels, solvents and chemicals. The sensing element is nestled safely in a ceramic package and is encased in a waterproof gel that prevents water that gets into the sensor from interfering with readings.

The LPS33HW has a 24bit pressure data and 16 bit temperature data, allowing it to deliver pressure readings with +/- 0.1% hPa accuracy. It can measure from 260 to 1260 hPa and is able to withstand pressure up to 20 times its measurement range. To help you take measurements to your requirements, the LPS33HW also offers an adjustable data rate, as well as a low pass filter to remove noise from the signal. Finally, the onboard temperature compensation makes sure that your readings are always good and won't vary as the temperature changes.

This sensor has a metal port with a lip that can be used to install an O-ring. This model we found on McMaster seems to work well. We also stock the sister-product, the LPS35HW which is not ported. Please note the port is not a strong mechanical connection so make sure not to put side-shear force on it!

To make life easier so you can focus on your important work, we've taken the sensor and put it onto a breakout PCB along with support circuitry to let you use this little wonder with 3.3V (Feather/Raspberry Pi) or 5V (Arduino/ Metro328) logic levels. Additionally since it speaks I2C you can easily connect it up with two wires (plus power and ground!).  We've even included SparkFun qwiic compatible STEMMA QT connectors for the I2C bus so you don't even need to solder! Just wire up to your favorite micro and you can use our CircuitPython/Python or Arduino drivers to easily interface with the LPS33ASAP.

Please Note: The sensor itself is advertised as Water/Chemical Resistant, but the breakout board for testing out this sensor is not! If you want to use it in wet environments, you'll need to put the rest of the board in a waterproof epoxy!

Check the tutorial for example code for Arduino and CircuitPython, pinouts, assembly, wiring, downloads, and more!