Hey buton,
sorry, I did not see your previous post. I am impressed of your code, I myself have no idea about bit banging. Way to go, I saw your video, very nice.
At work I use the MS5803 sensor which is also very interesting, same size, but with both an I2C and SPI interface. And you could actually use the logging device for climbing as well 
So keep us updated about the mechanical work which is coming up, especially how to get the sensor sealed and water tight.
Greetings