kopia lustrzana https://github.com/aa1gd/pico_ft8_xcvr
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| fft | ||
| ft8 | ||
| peripheral_util | ||
| tests | ||
| util | ||
| .gitignore | ||
| CMakeLists.txt | ||
| LICENSE | ||
| README.md | ||
| TODO.txt | ||
| decodedmessages.jpg | ||
| pico_sdk_import.cmake | ||
| run_ft8.c | ||
README.md
Raspberry Pi Pico FT8 Transciever
Run FT8 on the $4 Raspberry Pi Pico microcontroller! This code, based on Karlis Goba's (YL3JG) FT8 Library, runs a standalone FT8 amateur radio transciever.
It does the following:
- Decodes FT8 signals in real-time.
- Displays decoded signals and a spectrum waterfall on a ST7789 240x320 LCD display.
- Controls a Si5351 programmable oscillator used for a direct conversion reciever, and for driving a Class-E amplifier during transmission.
- Encodes response messages based on recieved messages and user selection.
- Reads in user selection from a 4x4 membrane keyboard.
- Offers a startup screen where time is calibrated to the second to ensure proper reception/transmission intervals.
Technical Notes
- This code implements incremental decoding. The Pico only has around 200kB of RAM. It is not possible to store a 15 second duration of samples, and thus samples are collected in ~1 second intervals, processed with the FFT, and only the FFT data is stored.
- The Pico has a dual-core processor. This code uses multithreading, using one core to control the functionality of the transciever (display, ADC readings, etc.) and the other core to do signal processing (FFT and error correction codes).
- This code overclocks the Pico's processor, since running at normal clock frequency, it is unable to keep up with decoding all samples within the 15 second transmission interval.
- The audio-frequency FT8 signals are fed into the built-in ADC on the Pico. The Pico has the ability to sample two analog inputs, but only one is used right now. In the future both can be used for quadrature signals coming out of a direct conversion reciever so the transciever can have sideband rejection.
Development
- Set up the Raspberry Pi Pico C/C++ SDK, as described here.
- My apologies for the sloppy code quality. I coded this in high school, before I took a proper programming class. I've improved since then.
- See Dhiru Kholia's (VU3CER) fork of my code for his own transciever project. His project has details on how to implement it in hardware.