I just discovered that the stuff sent through the serial port of my laptop behaves really strange.
I use Hyperterminal, and a USB-to-RS232 adapter. I have an oscilloscope connected to the RS232 signal also. When I press and hold a key, I can see on the oscilloscope that every other time the laptop sends the ASCII code with the highest bit wrongly set to 1! WTF?
What's even more strange, if I just press some different random keys, and then go back to press and hold one key, the laptop will send the correct ASCII code each time!
This is a really strange behaviour, and I have absolutely no idea why it appears. I use 19200 baud, 8 data bits, no parity, 1 stop bit. Please, can anyone help me?
BTW, sorry for this not being an AVR-specific question. :oops: