[Linux-ham] soundmodem

[folkert]

Hi,

I'm planning on building a soundmodem setup with my raspberry pi.
At http://i.stack.imgur.com/Y2J1W.gif there's a schema for creating a
PTT switch with a real serial port. The RPI does not have RTS/CTS but
tons of GPIO pins. Now GPIO pins work with 3,3v and RS232 is at 12v so I
think I need to increase the 10k Ohm resistor? Or decrease it? Probably
decrease it as (guessing here) the 10k was there to reduce the voltage
on the trigger-pin of the transistor? Any help is appreciated.


regards,

Folkert van Heusden

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