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I have an ASUS RP-AC51. It doesn't broadcast any WiFi network when powered on, the management interface cannot be accessed over Ethernet, and the reset button seemingly does nothing.

I decided to try and get a shell on the device with UART. I'm following the instructions from this video. Here are photos of my setup.

I use screen on the Pi to connect to the device:

pi@desk:~ $ lsusb
Bus 001 Device 004: ID 0b95:772a ASIX Electronics Corp. AX88772A Fast Ethernet
Bus 001 Device 003: ID 1a86:7523 QinHeng Electronics CH340 serial converter
Bus 001 Device 002: ID 1a40:0101 Terminus Technology Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
pi@desk:~ $ ls /dev | grep USB
ttyUSB0
pi@desk:~ $ screen /dev/ttyUSB0 300

I tried every single one of the common baud rates listed in the video. I never got any readable text. As an example, here's a snippet of what I get at 115200:

E�I�L)rNS:9
            4�"�*.W PFd���QN'S�Jj
PS� ��3Z�Y L    rr$j             �HR
                    -B����Y":j
                              0�VH. ��)j
                                        ath_!�J��+,W+�5��e��)�BHL��*W   "2J���WHa�5幮e�VVՕ�k�'�,յ�M"�J l9
          ��R��p@ ₂����RT� Plk  B��+E |         �6      ��2FJ!U�څ(es�'B�1       �L      ��L   ��1S�1` R�AU1b��J��
                  j
PS:��              ARU*R

Does anyone know what baud rate I should be using? Or am I doing something else wrong?

(I don't have an oscilloscope.)

1 Answer 1

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Looking at another device of the same family seems you need this configuration for the UART interface:

  • baud rate: 57600
  • data bit: 8
  • parity: N
  • stop bit: 1

57600/8-N-1 (in short notation).

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  • I set this configuration with stty -F /dev/ttyUSB0 cs8 -parenb -cstopb, then used screen /dev/ttyUSB0 57600 to connect. Still got unreadable output.
    – localhost
    Dec 20, 2021 at 17:03
  • You double-checked if RX and TX are in the right place? BTW you can configure all the parameters directly from Screen itself :)
    – zi0Black
    Dec 27, 2021 at 16:21
  • Yes, triple-checked even. Maybe it's just bricked or something.
    – localhost
    Dec 28, 2021 at 8:41
  • Did you try changing the adapter? You properly placed GND (adapter) ->GND(board)?
    – zi0Black
    Dec 29, 2021 at 15:18
  • Yes, the ground pins are connected (as you can see in photos 2 and 3). This is the only adapter I have. It's brand new.
    – localhost
    Dec 29, 2021 at 17:11

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