The sensor on the BerryGPS-IMU is the BMP280. I have just updated the GIT repo with code which can be used;
https://github.com/mwilliams03/BerryIMU/tree/master/python-BMP280-temperature-pressure
Regarding Gyro values changing, this is from noise and all gyroscope exhibit this behavior. This is why the values from the accelerometer and gyroscope need to be fused. See this guide;
https://ozzmaker.com/berryimu/
Mark --OzzMaker.com --
