On some HD44780 boards (eg the Keyestudio LCD1602 expansion shield),
the RW pin isn't brought out and is permanently grounded.
This means that the board can't be read from, and in particular the
busy status can't be read.
This patch adapts the package to work with boards like these.
To signal this to the package, set the RW pin to machine.NoPin.
The package will then disallow all reading and use adjustable timing
based writing. The timing can be adjusted the configuration.
Patricio Whittingslow
deadprogram
Drayton Munster
Nick Craig-Wood
Daniel Esteban
k-brk