DS18B20 & LCD w/I2C piggyback

celsius & fahrenheit temp displayed on 2 line LCD

Many thanks to AlexanderS for the basis of the code: https://gist.github.com/AlexanderSavochkin/6045dad44130bbff80db

A simple build that allows an LCD (with I2C piggyback) to display temperature in both celsius and fahrenheit. Temp is pulled from a waterproof Dallas Temperature sensor DS18B20 with 1M lead.