Universal LCD Module

Interfacing an LCD to a microcontroller system is daily bread and butter for the average electronics engineer. There are innumerable variants and many circuit suggestions for interfacing the six to seven LCD signals to a microcontroller system. In an effort to prevent continual reinvention of the wheel the author of this design used this simple formula:
(LCD module + Atmel controller) + (a touch of software) = (universal display module)
to design this versatile display unit and PCB.

Resistors

R1 = see text

Capacitors

C1,C5 = 100nF

C2, C3 = 27pF

C4 = 10µF 16V radial

Semiconductors

D1-D4 = 1N4148

T1 = BS170

IC1 = AT90S2313, order code 050259-41

Miscellaneous

X1 = 11.0592MHz quartz crystal

S1-S16 = pushbutton type D6

LCD module, 2x16 characters

PCBs, ref. 050259-1