ValueError -1 ValueError 0 UART 1 UART 2 ValueError 5 UART 6 UART(1, baudrate=9600, bits=8, parity=None, stop=1, flow=0, timeout=0, timeout_char=3, rxbuf=64) UART(1, baudrate=2400, bits=8, parity=None, stop=1, flow=0, timeout=0, timeout_char=7, rxbuf=64) 0 3 4 None 1 4 None None UART(1, baudrate=9600, bits=8, parity=None, stop=1, flow=0, timeout=0, timeout_char=3, rxbuf=8) UART(1, baudrate=9600, bits=8, parity=None, stop=1, flow=0, timeout=0, timeout_char=3, rxbuf=0) UART(1, baudrate=9600, bits=8, parity=None, stop=1, flow=0, timeout=0, timeout_char=3, rxbuf=4) UART(1, baudrate=9600, bits=8, parity=None, stop=1, flow=0, timeout=0, timeout_char=3, rxbuf=0)