BPI-M1 UART interface

BPI-M1 have 4 UART port on board.
How to use serial port with minicom.
1 use ssh connect to BPI-M1 and install minicom
sudo apt-get install minicom
2 choose serial port
minicom -s
Uart port for BPI-M1
now , we test UART2 ,setting as below:
exit, minicom runing:
check Uart number:
dmesg | grep ttyS*
so you can see UART0 is ttyS1
3 you can use windows hyperterminal or putty on you PC,and setting the right Uart number.
4,test function:
BPI-M1 send "hello, pc"
BPI-M1 receive " hello Ok"
5 you can use the same way to test UART3(ttyS2)、UART7(ttyS3).so all is working fine.