Jim,

> There are various timing tables for HD44780 operations in the
> data sheet which can be used. Makes it a lot simpler

I'm aware of the "just wait for a bit" solution (no pun intended :-) ).  But
both the need to have to specify the timings for all kinds of different
actions (complicates the matter) as well as the doubt if it wil work for any
random connected display made me choose polling the busy line over it.
Dependability over simplenes I'm afraid.

> and you would generate a hell of a lot of I2C traffic.

:-)  Thats why I normally stick a small delay into the loop.   Long enough
to give other calls a chance, and short enough to keep the overall delay
small.

Regards,
Rudy Wieser

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