Serial monitor

Read the board’s log from this page and save it to a file. No terminal to install, no drivers to find, and nothing leaves your browser — the log is never uploaded anywhere.

Not connected.

Not at the board? Paste a log instead

A log somebody sent you, or one downloaded from the device (Settings → System → Download log). It gets the same colouring and the same Save button. 



  

    
What to expect

    
    
      
  1. Connect the board to this computer with a USB cable.
    2. 
      
  2. 
        Press Connect and pick the board’s port. On Linux
        it is usually /dev/ttyACM0 or /dev/ttyUSB0; on
        Windows a COM port; on macOS a usbmodem or
        usbserial entry.
      
    3. 
      
  3. 
        The log appears as it arrives. Panics, warnings and the boot banner are
        coloured so they are findable in a long capture.
      
    4. 
      
  4. 
        Press Save to file and attach the file to your issue or
        discussion. That single file usually answers a question that would
        otherwise take a week of messages.
      
    5. 
    


    

      This page only listens. It never writes to the port, and it clears DTR and
      RTS as soon as the port opens — asserting those is what holds a board
      in reset or drops it into the ROM loader, and a monitor that did it would
      change the very thing you are trying to watch.
    


    
If the log is empty

    
    
      
  • 
        The board resets when the port opens. On boards whose
        USB goes straight to the ESP32-P4 (the Function EV, for example) opening
        the port restarts the chip, so what you see starts at the boot banner.
        That is normal. On the Waveshare ESP32-P4-ETH the USB-C is a CH343
        bridge and the board keeps running.
      
    • 
      
  • 
        Nothing at all, at any speed. Check the cable: some USB-C
        cables carry power only. And make sure nothing else has the port open -
        a terminal, an IDE monitor, or a flashing tool still running.
      
    • 
      
  • 
        Garbage characters. Wrong speed. ESP-KVM logs at 115200.
      
    • 
      
  • 
        The port is not in the list. On Linux your user may not
        be in the dialout group; on Windows and macOS a CH34x board
        needs its driver. The
        flashing page has the same notes in more detail.
      
    •