Installing Serial on the Asus Tinker Board

Configuring UART to use as a serial port
Created: 11/02/2017 | Last Updated: 11/02/2017

The Tinker Board contains UART on pins 8 and 10, the same as on the Raspberry Pi GPIO port.  The Debian Linux supplied by Asus has the UART enabled by default as a serial console on ttyS1 with a baud rate of 115200.

To use the UART pins for serial communication with our Serial Pi Plus or RS485 Pi you will need to disable the console on ttyS1. 

There are two ways you can disable the console on TinkerOS Debian.

Method 1:

Remove the SD card containing the Debian image from the Tinker Board and plug it into a card reader on your PC.  Open the card in your file manager and select the extlinux folder.

There should be a file called extlinux.conf, open this in your text editor.

The text file should contain the following text:

label kernel-4.4
     kernel /zImage
     fdt /rk3288-miniarm.dtb
    append  earlyprintk console=ttyS1,115200n8 root=/dev/mmcblk0p2 rw init=/sbin/init

Remove the console section from the text file so it now reads:

label kernel-4.4
        kernel /zImage
        fdt /rk3288-miniarm.dtb
        append  earlyprintk root=/dev/mmcblk0p2 rw init=/sbin/init

Save the file and put the SD card back into the Tinker Board.  When the board boots the UART port should now be accessible from a terminal program on /dev/ttyS1.

Method 2:

Within Linux on the Tinker Board open the file /media/linaro/D32E-178C/extlinux/extlinux.conf using nano.

sudo nano /media/linaro/D32E-178C/extlinux/extlinux.conf

If nano is not installed you can install it using:

sudo apt-get install nano

Edit the file the same way as in method 1 removing the console section.  Save the file using Ctrl-x and y.

Reboot the Tinker Board.

sudo reboot

When the board reboots the UART port should now be accessible from a terminal program on /dev/ttyS1.