BME280 build: When Altitude is entered in meters the IOControl display shows altitude "meters entered -1" #205
Description
In the BME280 build the altitude entry made via the REST command /81 always shows up in the IOControl display as 1 meter less than what was entered.
I've looked into this and it is the result of value truncation due to use of integers instead of floats, and the use of "feet" in all internal calculations in the BME280 driver. The use of feet in the driver was a matter of the source code copied from Bosch. So, when a user enters altitude in meters it is converted to feet and stored in EEPROM for use by the driver. This conversion results in the first truncation, then later when the altitude value is displayed in the IOControl page it is converted from feet back to meters, resulting in another truncation.
These "truncation errors" do not result in any significant error in the calculation of barometric pressure, It only causes a little confusion for the user when altitude is not reflected in the display as entered. It is a fairly simple fix, so I'll take care of it in the next release.