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.
Just add a button between Pin 27 (GP21) and Pin 36 (3V3) 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 build/pico-wspr-tx.uf2 file to the
Pico board.
mkdir -p ~/repos
cd ~/repos
git clone https://github.com/raspberrypi/pico-sdk.git
export PICO_SDK_PATH=$HOME/repos/pico-sdk
./build.sh
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.
Please note that the signal generated by the Pico is not a very clean one. A BPF must be placed between the Pico's output and the amplifier.
https://github.com/kholia/HF-PA-v10/tree/master/IRFP-Hacks-v5-SMD is a pretty decent amplifier design for 5W to 20W.
You can also try the 2W Amplifier 1-930MHz module that is available on
Amazon, and other places.
