Prototype USB to ST4 guide output


PIC based (18F2550) for USB interface as CDC interface (USB-serial port)

Use same ASCOM driver as the native USB-TTL serial 909 clone for guide control
Opto-isolated from scope

Update 5/1/2009, PCB ordered


Relay adapter board, plugs into socket of PS2501-4 chip


Anything or nothing may change in the future, this does work built as shown





Prototype parts list, note PS2501-4 now used, not PS2502-4


Prototype schematic (as built) (click on pic for full size PDF)
Note: change from below, RB7 is now RA3 in PCB version (SW2 to RA3)



Pic of first draft top layer PCB, no room for the led's yet. 25x400 mm