Rock Pi S with 3 UART (Hardware v1.1)


i have all 3 UART enabled and only UART 0 and UART 1 works. UART 2 isn’t working at all. Is there any known issue? I currently need all 3 of them.

Thanks & Regards.


both pins (rx/tx) work in GPIO mode as expected but as UART2 this pins doesn’t work.

It seems the Kernel DTS is buggy. This ugly patch will fix it:
But it will disable wireless and uart0 rts/cts functions but it works for me because i have a no wifi board.
Would be nice if you can fix it in the future.

The next problem is u-boot, it will stop the autoboot if there is any data on UART0 …


uart2 (/dev/ttyS2) is still buggy on Hardware V1.2 without BT Wifi on debian buster (2020-03-16) updated (26.05.2020) with versions
rockchip-overlay 2.6
kernel 4.4.143-47-rockchip-g495ff574976c

this enables the kernel console on uart2, but it should not

this enables the kernel console on uart2, but with unreadable output

Hi ,I suggest that you use this image

To use 3 UARTs, you can view the " Common Hardware Interfaces" part of

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Hi, I got the debian buster (2020-03-16) image working. I will also try the newer image, thanks.
Regarding the debian buster (2020-03-16) image:
The uart2 is configured serial-console at default in boot.cmd. To disable it, one has to unset console in uEnv.txt. Example:

In uEnv.txt

This disables the serial console on uart2, which enabled by default in debian buster (2020-03-16). Interestingly choosing rk3308-console-on-uart2 with default settings gives double output of console to uart2, which results in unreadable gibberish.

The new debian image is also working, and easier to configure, thank you.