CPAP prssure tester

Having recently been advised I need to use a CPAP machine, I decided to toss together a pressure tester as one of the machines we have I was unsure if the calibration was correct.
Here is the first rough test version. The slot the BMP180 is inserted through is just taped up at the moment. Later, I intend to make a full case.

The pressure sensor I have used is the BMP180 as that is what I've got on hand.
The processor is an Arduino Pro mini, and a small I2C OLED display is added.

The sens