Flashing (tr)uSDX Firmware on Linux - Complete Guide

Step 1: Install Mono

Mono allows you to run .NET applications natively on Linux, which means you'll see Linux device names instead of dealing with Windows COM port mapping.

sudo apt update
sudo apt install mono-complete

Step 2: Add Your User to the dialout Group

This gives you permission to access serial devices without needing sudo every time.

sudo usermod -a -G dialout $USER

Step 3: Download the Firmware

Download the latest (tr)uSDX firmware from the official source:

Save the .hex file somewhere you can easily find it, like:

/home/yourusername/Downloads/

Step 4: Download and Extract avrdudess

Download avrdudess from the official website:

You want version 2.20 or later. This will download as a .zip file.

Extract the downloaded file:

You can extract it using your file manager (right-click → Extract Here) or from the command line:

cd ~/Downloads
unzip avrdudess-*.zip -d ~/avrdudess

This will create a folder at /home/yourusername/avrdudess/ containing the avrdudess.exe file and supporting files.

Step 5: Connect Your Radio

1. Power on your radio (some radios need to be on to accept firmware)
2. Connect it to your computer with a data-capable USB cable
3. Wait a moment for Linux to recognize it

Step 6: Identify Your Radio's Serial Port

Run this command to see which port your radio is on:

ls /dev/ttyUSB*

You should see something like /dev/ttyUSB0 appear. This is your radio.

Troubleshooting if nothing appears:

• Try a different USB cable (many cables are charge-only and won't work)
• Try unplugging and replugging while running: dmesg -w (press Ctrl+C to stop)
• Check if your radio needs to be in a specific programming mode

To verify which device was just connected, run:

lsusb

Look for a line mentioning "CH340 serial converter" or similar USB-to-serial adapter.

Step 7: Launch avrdudess with Mono

Navigate to where you extracted avrdudess and run:

cd ~/avrdudess/
mono avrdudess.exe

Step 8: Configure avrdudess

When the program opens, you'll see Linux device names in the dropdown menus. Configure it as follows:

Programmer Settings:

• Programmer: Select arduino (Arduino for bootloader using STK500 v1 protocol)
• Port: Select /dev/ttyUSB0 (or whatever device appeared in Step 6)
• Baud rate: 115200

MCU Settings:

• MCU: ATmega328P (for most (tr)uSDX radios)

Flash Settings:

• Click the ... button next to the Flash field
• Important: Navigate using the Linux file path (like /home/yourusername/Downloads/yourfirmware.hex)
• Do NOT use paths starting with Z:\ - those are Wine paths and won't work with Mono
• Select your firmware .hex file that you downloaded in Step 3

Step 9: Flash the Firmware

1. Double-check all your settings match above
2. Make sure your radio is powered on
3. Click the "Program!" button
4. Wait for the process to complete

You should see progress messages in the terminal window at the bottom. When it's done, you'll see "Ready" at the bottom of the window.

Common Issues and Solutions

sudo apt install avr-libc gcc-avr binutils-avr

Tips for Future Use

Create a Quick Launch Alias

Add this to your ~/.bashrc file:

alias avrdudess='cd ~/avrdudess && mono avrdudess.exe'

Then you can just type avrdudess in any terminal to launch it.

Remember Your Port

Your radio will usually be /dev/ttyUSB0 if it's the only USB serial device connected. If you have multiple devices, they'll be numbered sequentially (/dev/ttyUSB1, /dev/ttyUSB2, etc.).

Use Mono for Other Radio Software

Many Windows radio programming tools are .NET applications. Try running them with Mono first:

mono yourprogram.exe

If it works, you'll have the same easy Linux device access without COM port mapping headaches!