UART communication issue
't' looks like 000101110 on the line 0x80 like 000000001 and 0x00 like 000000000 (including the start bit an ignoring the stop bit)
 almost certainly you have the baud rate too fast at the receiving end.

given that you're seeing 0 zeros and a 1 it's probably set 8 times too fast, so try 1200 baud in cutecom and look for a possible cause for the baud rate divider in the arduino to be set 8 times too high.