The Bar30 pressure sensor is a high-pressure, high-resolution pressure sensor. With 0.2 bar resolution, it has an amazing depth measurement resolution of 2mm in the water column! It can also be use in air to measure altitude.
The sensor is the Measurement Specialties MS5837-30BA, which can measure up to 30 bar (300m depth) and communicates over I2C. It operates on 3.3V I2C voltage but can accept power input up to 5.5V. It includes four solder pads for ground, 3.3V-5.5V power, and 3.3V I2C lines.
This sensor includes a temperature sensor accurate to ±1°C, with data also accessible through I2C. If you need something with more temperature accuracy, please check out the Celsius Temperature Sensor.
The electrical schematic and board layout are open-source and the design files are available below. Feel free to adapt for your own needs.