RT3s Custom Firmware

This repo contains a non-functional, but most of the times working firmware for the RT3s handheld radio. The project resulted as an attempt to create a user-friendly entry into firmware hacking and development for the RT3s. I choose platform io, because most Maker are already familiar with it (Arduino), it also allows the compliation and upload of the firmware by the press of a button, which is quite nice.

Goals

• USB Serial
• USB Audio (Microphone and Speaker) needs more work
• Add FreeRTOS
• Implement USB Serial via FreeRTOS
• Analog 70cm / 2m RX
• Analog 70cm / 2m TX
• Keyboard input handler
• Display handler
• Remote control via PC
• Stream audio to radio from PC and vice versa (full remote control)
• ... more will follow

Flashing the Firmware

• Set the radio in the DFU mode (press the PTT button and the top button and turn on the radio)
• Now the top led should blink between red and green.
• Connect the radio to the PC via des USB cable
• Press the upload-button in vs-code (->)
• Now the programm should be compiled and uploaded to the radio.
• If an error occurs follow the following steps

Error Windows

• Can you find the radio in the device manager?
• If you launch radio_tool manually (located in /scripts/radio_tool/radio_tool.exe) with the parameter -h 1 does it print the help page. (CMD: ./radio_tool -h 1)
• If not you need to make radio_tool runnable maybe visite the radio_tool github repo for a new version: https://github.com/v0l/radio_tool
• If the help is displayed try running CMD: ./radio_tool.exe -l
• If no devices are listed try installing the WinUSB driver on the radio via zadig (https://zadig.akeo.ie/) (Tipp: if no devices are listed in zadig, go to options and check: "List All Devices") After that install the WinUSB driver on the radio.
• If you get the error message Failed to enumerate serial ports while running ./radio_tool.exe -l then you can fix this by plugging in any other devices that opens a serial port (COM port). After that you can unplug the serial devices and the tool should now work. This error is due to a missing registry entry in windows (HKEY_LOCAL_MACHINE\\HARDWARE\\DEVICEMAP\\SERIALCOMM)`and plugging in a serial devices creates this entry. (This bug was already reported: v0l/radio_tool#24)
• The build/flash pipline uses python3 so make sure that python3 is installed and useable via python3

Error Linux

• Make sure that the nessesary packages are installed for radio_tool and that python3 is installed and runnable via python3
• For radio_tool requirements you can visit the repo: https://github.com/v0l/radio_tool

Contribution

You can fork this repo and or contribute, but maybe get in touch with me first. See contact at the HTR website.

Special thanks

• Thanks to the FreeRTOS forum for helping me getting FreeRTOS running on the radio.
• Thanks to the creator of the radio_tool for creating a tool that makes the flashing process so much easier.
• Thanks to the OpenRTX project for helping getting started with my project, I hope I can contribute to them at a later time.

Additional Notes

This is more like a hobby project and in no way a standalone firmware. My main goals will be to get the RX and TX running and to maybe control the radio via USB from a PC (commands via usb-serial + audiostreaming (mic + speaker)).