Kaushlesh Chandel prototyped a few projects on his Arduino that use an HD44780 Character LCD. Wanting to keep these projects in one piece, but not sacrifice his Arduino board, so he etched his own LCD backpack that is Arduino compatible. If you’ve never made it past the Arduino board to build a module that only uses the parts you need for a project, this is a great source of inspiration for you to give it a try.
The design that Kaushlesh drew up is quite simple. It connects directly to the single in-line header of the character LCD. It looks like he’s using the 4-bit mode for addressing that display, which leaves you with quite a few pins (both digital and analog) to work with in the future. The important components rolled into his design are the chip itself, an ATmega8/168/328, the crystal to make sure it is running at the correct speed for Arduino timing, and a trimpot for adjusting the contrast on the display. The final feature you’ll want to be sure to include in your own design is a pin header for programming the chip via an FTDI cable.