Using 4 UART onboard

[Using 4 UART onboard]

Hi, I am try to use all the 4 UART on Tinkerboard. But I can only find ttyS0.

May I know what are the names of the other 3 UARTs? I was expecting something like ttyS1 ~ S4

Please give some advices

[GPIO High Low Voltage level]

I found this for Raspberry PI.

GPIO digital input voltage levels: <= 0,8 V results in a digital one. >= 1,3 V results in a digital zero.

May I know what is the case for Tinkerboard?

Anyone can help? 

[Mass Deployment of Tinkerboard]

I have created an image that is running from the eMMc.

After finishing testing, I would like to deploy the image to many Tinkerboard. 

May I know what is fastest method?

I do not want to use SD card.

Thanks in advance.

Alvin

[wifi\ble for thinker r2 Android]

I just booted up a R2 Tinkerboard with the latest OS Debian 10.But could not get the wifi working as well. 

I am running a production with Tinkerboard S and received R2 board.

I need am urgent response from ASUS on this matter. 

 

Thanks