For I2C comms with Wire.h lib, nano pins:
Nano A4 - SDA
Nano A5 - SCL
1602 LCD Pins - note the 220R for Vcc at pin 15 for power and a 5k contrast resistor if no 10k pot available to pin 3 from Gnd:
1hPa = 1 mBar, e.g. 1006.53 mBar
Analog pin 4 (SDA) and pin 5 (SCA) also used for TWI communication using Wire library.
Pins 0TX,1RX- if using serial lib...?! aha!
