With an UNO - 4 wires - +5, GND, SDA, SCL and 2 10k pullup resistors connected to +5, a simple 16x2 lcd display works as expected. Now substitute a pro mini for the UNO - the HELLO WORLD example produces only the letter H where it should be and nothing else. I have tried this with 2 new, pro minis with the same result. What am I missing?
Given the minuscule amount of information provided, how could anyone know?
Just tried something that worked. With ID# 1.6.5 and 1.5.8 the problem is as I stated. Withe 1.0.1 it works very well.
I will take this over to the Arduino forum.