First of all, many thanks to Roman for this brilliant WSPR project! The world has never seen a WSPR beacon on such an inexpensive and small hardware ;-).
Simply ingenious is the controller-controlled oscillator, which can be modulated to milliherzts - the heart of the beacon and the project!
As Roman writes in his project description: "It doesn't require any hardware - Pico board itself only."
With this fork, the first transmission of the beacon can be triggered by a button. And then, after the first transmission ends, it is repeated every 4 minutes controlled by the internal RTC of the Pi Pico. The interval for the following transmission can be configured.
Dhiru: This fork adds FT8 support.
NEW (Updated): Add a button between Pin 21 (GP16) and Pin 23 (GND) on the
Pico board.
The antenna connects to Pin 9 (GP6) on the Pico board.
Step 1: Configure the FT8 message (char *message = "CQ K1TE FN42";) to send
in the WSPRbeacon/WSPRbeacon.c file.
Step 2: Compile the project and copy the pico-wspr-tx.uf2 file to the
Pico board.
mkdir -p ~/repos
cd ~/repos
git clone --recursive https://github.com/raspberrypi/pico-sdk.git
export PICO_SDK_PATH=$HOME/repos/pico-sdk
cmake .; make -j4
./picoload.sh pico-wspr-tx.uf2 # optional
Step 3: Power the Pico board
Step 4: Wait for the start time of the next FT8 transfer window. Press the button to start the next broadcast.
Step 5: Use the WSJT-X software to check if the transfer is within the valid transfer window. If necessary, repeat the start procedure.
https://www.raspberrypi.com/documentation/pico-sdk/high_level.html#group_pico_aon_timer
Use this instead of RTC (hardware_rtc) which is unavailable on RP2350.
https://github.com/kholia/HF-PA-v10/tree/master/IRFP-Hacks-v5-SMD is a pretty rugged amplifier design for getting 1W to 30W RF output on all HF bands!
In a pinch, you can also try the 2W Amplifier 1-930MHz module that is
available on Amazon, and other places.
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Connect a 6v solar panel to the CN3791 module.
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Connect a 18650 cell to the 1S BMS (using B+ and B- pads).
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Connect the 1S BMS to the CN3791 module (using P+ and P- pads).
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Connect the load (the beacon system) to the CN3791 module.
