Arduino barometer BMP180 + Firefly plugin [can not read pressure difference]

Hello everyone,

I am currently working on barometric tool to measure human blowing pressure within the tube. 

Tool works just fine (with BMP180 barometer) Using Arduino I can read pressure values (exp. I can see how from 1004kPA it goes up to 1070kPA+)

It is a very simple circuit.

When I connect Arduino Uno to Grasshopper Firefly (Using Firefly_Firmata code) it reads values, however barometer does not seem to work. (Value is stuck ~1020) And not changing very much (not even close to the values I get while using Adafruit Arduino script)

I attached gh file also Arduino codes. Maybe there is something wrong with the script.

Firefly_Firmata - default code

BMP180 - Adafruit code for pressure read. And Temperature

Thank you!