This is a new project, a DSKY, the Display Keyboard interface for the Apollo Guidance Computer (AGC), using two 240x320 LCD screens and a keypad made with Kailh Cherry clone keys.
This DSKY uses an Arduino Mega 2560 to interface with the host computer via a USB Virtual Serial Port. The Arduino Mega uses two of its auxiliary serial ports to communicate with the Arduino Nano on each screen. The Arduino Mega is also responsible for scanning the DSKY keyboard and sending keypresses back to the host computer.
Each indicator on the left and right screen is controlled by a command from the host computer. For example to illuminate the indicators below, the host computer sends to the Mega the following string "C F P V00 N00 X 00000 Y 00000 Z 000 ". The Mega receives commands from the host computer and forwards them to both screens. The left screen reacts to single character commands A..O. Upper case commands illuminate an indicator, lower case commands turn them off. The right screen uses the Q command to illuminate the COMP ACTY indicator and the P, V, N, X, Y, Z commands to display numeric data which may include a leading positive or negative sign.