[I2C] BOSCH BMP085 air pressure
I2C1 and USART2 debug
* pressure in Pascal (Pa)
* 1 Pa  = 1 Newton/m^2
* 1 hPa = 100Pa
* 1 bar = 10^5 Pa = 1000hPa
* 1 atm = 1.01325 x 10^5 Pa = 1013.325 hPa