thank you, but I was wrong about 2. I do not need arduino limits. Let me ask again.
I'm trying to connect 501 UART to other devices (embedded android with GPIO or RS232/RS485 for example). There is no pure UART. I have to code it in software.
So I need c/java code to make UART on GPIO. Is it possible, don't you know?
Or it is abad idea and I have to buy some RS232-UART converter?