I made this library for the simple reason that I could not find a ready-made library that suited my needs.
These displays were used in old Nokia 5110/3310 cell phones. It is a 84x48 pixel monochrome LCD display. These displays are small, but very readable and come with backlight. This display is made of 84x48 individual pixels, so you can use it for graphics, text or bitmaps. These displays are inexpensive, easy to use, require only a few digital I/O pins and are fairly low power as well
To drive the display, you will need 5 digital output pins. Another pin can be used to control (via on/off or PWM) the backlight, but the library has no support for this function.
The display driver is a PCD8544 chip, and it runs at 3.3V so you will need a 3V supply handy. Logic levels must be 3V to prevent damage so you must use some kind of levelshifter.