Panelolu2 is an LCD and rotary encoder, based on the original Panelolu. It uses an I2C port expander to drive the LCD screen and adds a piezo buzzer and indication LEDs. This version uses less pins, making it compatible with the Melzi electronics and even leaves enough spare pins to drive a couple more outputs (such as an additional extractor fan and stepper driver cooling fan)
The Panelolu2 design simplifies the assembly by mounting all components on one circuit board that can be soldered directly to an LCD screen. The standard way to connect it to the screen is with a single row of 2.54mm headers as shown below. This row of headers could be replaced by wires (ribbon cable would be best) - enabling a variety of case designs. This simplification also extends to the wiring which is now a 2x6 IDC plug on both ends of a ribbon cable. The circuit uses a combination of through hole and surface mount components; the other side of the prototype circuit board is shown below. The brightness and contrast pots are now on the back of the board and can be adjusted through the rear of the case.
Where to buy
The enclosure is on thingiverse.com, as an OpenScad file and STL.
It is fully Open Hardware, all the files are available on Github
Instructions & Schematics
The instructions are on a number of blog posts by Tony from Think3dPrint3d.
todo: migrate them to this page