Cannot flash the firmware for ratdgo using the web utility

Hardware
1

hey @PaulWieland I purchased two ratdgo 2.5 and was trying to flash the firmware and I’m essentially stuck. I tried installing on MacOS, which led to a lot of frustration as I cannot get the devices to even get recognized by the USB stack, and on Ubuntu I see them in my device list:

Bus 008 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 007 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 002: ID 090c:1000 Silicon Motion, Inc. - Taiwan (formerly Feiya Technology Corp.) Flash Drive
Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 003: ID 18d1:5026 Google Inc. tk-x001
Bus 003 Device 002: ID 1a86:7523 QinHeng Electronics CH340 serial converter
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 0e8d:0608 MediaTek Inc. Wireless_Device
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

when I try flashing the device I see in the selector window:

USE Serial ttych341usb0 - paired

which invariably ends in

Failed to execute ‘open’ on ‘SerialPort’: Failed to open serial port.

the instructions on your site don’t say anything about how to fix this and there’s no way to file an issue or contact you so… here I am. Thanks in advance for your help.

2

Edit: I have a ratgdo 2.5i and solved it below. I can’t recommend this board more!

3

For Ubuntu at least (and for me) I’ve got it working.

  1. Something called britty was blocking me from using the correct serial port, I wasn’t even seeing Serial ttych341usb0 when I first read your post.

  2. I found other reports of the same issue, which led me to this guide

  3. I updated the britty rules with the following command and rebooted
    sudo ln -sf /dev/null /etc/udev/rules.d/85-brltty.rules

  4. Then I could see the right serial port for the ratgdo but still got the failed to open serial port error

  5. I figured it might be a permission thing at this point and found this post describing the same issue for a similar ESPHome device

  6. This gave me permission and then it connected on my next try
    sudo setfacl -m u:USERNAME:rw /dev/ttyCH341USB0