Simple scripts to cross compile common SDR apps to run directly on PlutoSDR
Shamelessly plagiarizing https://github.com/zuckschwerdt/PlutoSDR-Apps, here are a couple of scripts to cross compile common SDR apps to run directly on the PlutoSDR.
A big thank you to Eric (aka LamaBleu https://github.com/LamaBleu), who made me realize it's possible to run apps directly on the PlutoSDR, pointed me to his old repository of PlutoSDR apps (http://www.lamableu.net/pluto/ipk/ https://www.lamableu.net/pluto/readme.txt), and supported me along the way.
Linux/Ubuntu machine Linaro toolchain as per https://wiki.analog.com/university/tools/pluto/devs/embedded_code, environment variables properly set
Once the prerequisites are met, create a work directory, and copy the included files. Make the cross_build.sh script and the file stripping utility arm-linux-gnueabihf-strip executable. Execute cross_build.sh, and everything should work. I added "Press any key to continue" after each major step to help understand what is going on.
Assuming that all the steps are correctly executed, a couple of files are created in the work directory: plutosdr-apps.tar and plutosdr-apps.zip. As of this writing, the .tar file is roughly 1.5Mbyte in size. Copy the .tar file to the PlutoSDR with:
scp plutosdr-apps.tar root@192.168.2.1:/tmp (check that the IP address is the correct one for PlutoSDR, and enter the correct password, usually analog)
then log into PlutoSDR with ssh root@192.168.2.1 and issue the following commands
tar -xvf /tmp/plutosdr-apps.tar
The output should look like this
usr/
usr/lib/
usr/lib/libSoapySDR.so.0.8.1
usr/lib/pkgconfig/
usr/lib/pkgconfig/SoapySDR.pc
usr/lib/libSoapySDR.so.0.8
usr/lib/SoapySDR/
usr/lib/SoapySDR/modules0.8/
usr/lib/SoapySDR/modules0.8/libPlutoSDRSupport.so
usr/lib/libSoapySDR.so
usr/bin/
usr/bin/SoapySDRUtil
usr/bin/rtl_433
usr/bin/rx_sdr
usr/bin/rx_fm
usr/bin/rx_power
At this point the plutosdr-apps.tar file can be deleted. And rtl_433 or rx_fm can be executed directly on PlutoSDR, for example rtl_433 -d driver=plutosdr -f 433M -g 20
The script is working without errors as of March 2022, with firmware 0.34w. Changes to the firmware or the upstream projects might break things, but hopefully the script and Toolchain.cmake are easy to follow and modify The script is not optimized for multiple runs (e.g. downloads sysroot every time), but can be executed multiple times and only changed files are recompiled
SoapyPlutoSDR is written to look for PlutSDR either as local, IP or USB. If compiled unchanged, the code will print an error message due to the lack of USB, and will wait for a timeout on the network search. Having to wait a few seconds every time a program is launched gets old rather quickly. The problem can be easily fixed by editing PlutoSDR_Registration.cpp from
// Backends can error, scan each one individually
std::vector<std::string> backends = {"local", "usb", "ip"};
to
// Backends can error, scan each one individually
std::vector<std::string> backends = {"local"};