On Nov 16, 2007, at 4:38 AM, Peter Feucht wrote:

> I saw an application note for a
> RS232-to-PIC(5V) interface which worked without any external power  
> supply,
> but it took the needed voltages from some pins of the serial port.  
> It had
> just a RS232 9 pole Dsub and 3 Pins (Rx,Tx,GND) on the PIC side.

Like the circuit used on the Serial Arduino?
http://www.arduino.cc/en/Main/ArduinoBoardSerialSingleSided

Beware; there's a backward cap in the schematic!  I think.

BillW

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