# Build instructions

This project uses the simple PlatformIO build system. You can use the IDE, but for brevity
in these instructions I describe use of their command line tool.

1. Purchase a suitable radio (see above)
2. Install [PlatformIO](https://platformio.org/platformio-ide)
3. Download this git repo and cd into it
4. If you are outside the USA, edit [platformio.ini](/platformio.ini) to set the correct frequency range for your country. The line you need to change starts with "hw_version" and instructions are provided above that line. Options are provided for EU433, EU835, CN, JP and US. Pull-requests eagerly accepted for other countries.
5. Plug the radio into your USB port
6. Type "pio run --environment XXX -t upload" (This command will fetch dependencies, build the project and install it on the board via USB). For XXX, use the board type you have (either tbeam, heltec, ttgo-lora32-v1, ttgo-lora32-v2).
7. Platform IO also installs a very nice VisualStudio Code based IDE, see their [tutorial](https://docs.platformio.org/en/latest/tutorials/espressif32/arduino_debugging_unit_testing.html) if you'd like to use it.

## Decoding stack traces

If you get a crash, you can decode the addresses from the `Backtrace:` line:

1. Save the `Backtrace: 0x....` line to a file, e.g., `backtrace.txt`.
2. Run `bin/exception_decoder.py backtrace.txt` (this uses symbols from the
   last `firmware.elf`, so you must be running the same binary that's still in
   your `.pio/build` directory).
