Optimizations for I2C library?

[RobTillaart]

Hi,

First, thank you for your excellent library!

As I was in the need for speed, I investigated if I could write a faster I2C liquid display library.
After a week the code (0.1.2) is reasonable stable and performance is meeting my needs.

It might be interesting to look at some of the optimizations I made to include in your I2C part.
Most important the library send a byte in one transaction of 5 bytes instead of using 4 transaction (one per nibble).
The PCF8574 handles this nicely.
Furthermore as the 4 data pins are in ascending order one can prepare the byte a bit faster.

I tried to keep the API similar to your library however I have not implemented all functions fully yet.
Finally I added a few new functions, e.g. clearEOL() and some more.

The link is: https://github.com/RobTillaart/I2C_LCD and should be available through the library manager.

If there are questions, please let me know.

Regards,
Rob