Serial connection on Edge-V

I bought the that is mentioned in Setup Serial Tool to use with the Edge-V, but the adapter comes with no instructions and the Khadas documentation doesn’t tell me which pins on the Edge-V I am supposed to connect to. Please help.

Hello @Melab

It is on the gpio header, please check here: Edge1 Hardware Documentation [Khadas Docs]

Are RXD, TXD, and GND the only pins I need to use? Do I match the GND pin on the Edge-V to the GND pin on the USB-TTL adapter board, RXD to RXD, and so forth? What about VCC? Do I use the 3.3V pin on the adapter board? The 5V pin?

I have gone ahead and connected the pins. After following minicom setup instructions and rebooting the device, I cannot see any serial output while in minicom. How do I do this?


  • BOARD GND <-> USB-TTL adapter GND
  • BOARD TXD <-> USB-TTL adapter RX
  • BOARD RXD <-> USB-TTL adapter TX

VCC is optional, you can leave it o disconnected or connected it to 3.3V or 5.0V depends on your USB-TTL adapter.

Please make sure you have setup minicom correctly.

  • Choose the correct serial devices, if you only have one USB-TTL adapter, it shuould be /dev/ttyUSB0
  • Setup correct baudrate - 1500000
  • Setup no Hardware Flow Control

It shuld be like this:

Welcome to minicom 2.8                                                                                                                                
Port| A -    Serial Device      : /dev/ttyUSB0                              |                                                                         
    | B - Lockfile Location     : /var/lock                                 |                                                                         
Pres| C -   Callin Program      :                                           |                                                                         
    | D -  Callout Program      :                                           |                                                                         
    | E -    Bps/Par/Bits       : 1500000 8N1                               |                                                                         
    | F - Hardware Flow Control : No                                        |                                                                         
    | G - Software Flow Control : No                                        |                                                                         
    | H -     RS485 Enable      : No                                        |                                                                         
    | I -   RS485 Rts On Send   : No                                        |                                                                         
    | J -  RS485 Rts After Send : No                                        |                                                                         
    | K -  RS485 Rx During Tx   : No                                        |                                                                         
    | L -  RS485 Terminate Bus  : No                                        |                                                                         
    | M - RS485 Delay Rts Before: 0                                         |                                                                         
    | N - RS485 Delay Rts After : 0                                         |                                                                         
    |                                                                       |                                                                         
    |    Change which setting?                                              |                                                                         

The correct baud rate is 1500000 and not 115200? 1500000 is not available.

I am getting output now, but it’s mostly garbage until I get to the Ubuntu login screen. Sometimes there is a BL31 message mixed in.

I want to be interacting with Ubuntu though, not Ubuntu. The steps to get to the U-Boot menu (resetting and pressing SPACE, or, booting into SD card and pressing SPACE) just outputs garbage that then doesn’t present me with printable characters.

@numbqq Can I get some more advice?

Yes, must be 1500000.

What’s the baudrate you set?

I was given a menu of possible settings and that was not one of the options. Is there a way to set it to a custom rate?

It’s set to 115200 8IN1.

What’s the system you used? If minicom doesn’t work for you, you can also try screen command.

sudo screen /dev/ttyUSB0 1500000

No, must be 1500000 8IN1

Does the baud rate have some connection to character decoding?

Ubuntu 20.04 on a PC.

I’ve set it back up again and tried minicom before screen to see if output is working again, but I’m getting nothing.

I did figure out how to set the baud rate to 1500000 on minicom afterwards though trying it again still displayed no output.

Hello @Melab

Could you please check whether the tty device on your host PC?

ls -al /dev/ttyUSB*