ARPIE Hardware Info

Parts List

Header Pins Labels

(*) KS1/KS2/ENA/DAT/SCK
Keys and LEDs are scanned by two 74HC595 shift registers. A single HIGH bit is clocked in (DAT/SCK) then clocked along all 16 shift register outputs in turn. For any output position ENA is pulled low to illuminate the associated LED and KS1 returns HIGH (pulldown needed) if associated menu button is down and KS2 returns HIGH (pulldown needed) if associated menu button is pressed. SCK is connected to both shift and store clock pins of both registers so a clock cycle is needed before the input pulse appears at the first output.

Schematics

Board Layouts