> For the complete documentation index, see [llms.txt](https://bananapi.gitbook.io/bpi-m1/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://bananapi.gitbook.io/bpi-m1/en/bpi-m1uartinterface.md).

# 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
```

![](/files/-M2HX-L0HwDbM3UWZCA8)

2 choose serial port

```
minicom -s
```

![](/files/-M2HX-L2MJBnUtqfXbR_)

Uart port for BPI-M1

![](/files/-M2HX-L4yDRwqxBh_3ic)

now , we test UART2 ,setting as below:

![](/files/-M2HX-L69UtBcAq4NZA4)

save:

![](/files/-M2HX-L8nKjBtTlKmSp-)

exit, minicom runing:

![](/files/-M2HX-LAB3uNBz2GOLgz)

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.

![](/files/-M2HX-LCeb2DXQVG8gW8)

4,test function:

BPI-M1 send "hello, pc"

![](/files/-M2HX-LEXeyWYdcmQUYB)

BPI-M1 receive " hello Ok"

![](/files/-M2HX-LGwjnNEFKRG6tf)

5 you can use the same way to test UART3(ttyS2)、UART7(ttyS3).so all is working fine.

![](/files/-M2HX-LIQTrvTQ8jyV8u)