PlutoSDR

The documentation is available on the Github Pages.

Using the radio through USB.

using AdalmPluto;

# Opening the radio with 100MHz carrier frequency, 3MHz sampling rate, and 64dB gain.
radio = openPluto(Int(100e6), Int(3e6), 64; bandwidth=Int(20e6));

# Receive the samples
sig = zeros(ComplexF32, 1024*1024) # 1 MiS buffer
recv!(sig, radio);

# Do some treatment
# ...
# ...

# Close the radio
close(radio);

This example records a few seconds of FM radio as WAV to .../AdalmPluto.jl/examples/samples/fm.wav. The duration and station selection have to be modified by editing .../AdalmPluto.jl/examples/fm.jl.

To launch the example (from the root folder of the project) : julia --startup-file=no --project=./examples ./examples/fm.jl.

The actual sampling rate has been measured using the file benchmark.jl. The full results of the last run is available in bench_results.txt.

The functions timed are :

• C_iio_buffer_refill alone, which queries samples from the hardware.
• C_iio_buffer_refill and two C_iio_channel_read for the IQ channels. The read function demultiplexes and converts to host format the data.
• AdalmPluto.refillJuliaBufferRX which is the same thing as before with reinterpret added to convert the samples to ComplexF32.
• recv! which calls the previous function and reads from the Julia buffer into the target array.

With julia lauched from the example folder :

julia> include("benchmark.jl");
julia> plot, results = bench_all();
julia> plot # to display a (very) basic unicode plot

This takes quite a while as each results are timed separately and the radio saturates quite quickly.

The artifact used for the proof of concept is hosted here.

It has been compiled using the following options :

git clone https://github.com/analogdevicesinc/libiio.git
cd libiio
mkdir build
cd build
cmake ../ -DCMAKE_BUILD_TYPE=Release -DWITH_LOCAL_CONFIG=OFF -DINSTALL_UDEV_RULE=OFF -DWITH_USB_BACKEND=YES -DWITH_NETWORK_BACKEND=YES -DWITH_LOCAL_BACKEND=YES -DWITH_XML_BACKEND=YES -DWITH_SERIAL_BACKEND=NO -DWITH_EXAMPLES=YES
make -j$(nproc)
tar cvzf libiio-0.21-custom.tar.gz libiio.so* tests/iio_* iiod/iiod .version

In order to work properly, the artifact needs a udev rule to access the USB peripherals. It is written in a volatile folder, hence the need the input the sudo password after each reboot. The password prompt does not come from Julia and no information about the password goes through julia. See the __init__ in .../AdalmPluto.jl/src/libIIO/libIIO.jl for more details.