USB to serial adapterBe aware that in the direction adapter to microcontroller (output from the PC), the signal could be positive and negative (between -12 to -3V for one logic value, and between +3 to +12V for the other one), so you may want to install a clamping diode in the input to the microcontroller. Check it !
In the other direction, the microcontroller signal of 0 to 5V will be recognized by the adapter as a valid signal, as it was by modern serial ports on PC when they had a serial port.
Also check for logic inversion (RS232: positive = logic 0, negative = logic 1)
Full information in wikipedia:
http://en.wikipedia.org/wiki/RS-232Note also that buffering of the data may occur, giving timing problems for some applcations. Anyway Windows is not a real-time operating system !
Phil.
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