Hello again
case is closed, the compiled library was put is /usr/local/lib, but an armv7 version was present in /usr/lib/arm-linux-gnueabihf, taking precedence over the other. just overwrote the bad one and everything is fine.
Thanks again
Best regards
Olivier

Thank you for your quick response. I'm not so quick due to coronavirus situation.
Very happy to know it works, so the problem is on my side. I'm gonna recheck everything, looks like libphidget22extra was not properly compiled.
Thanks for your help, I'll keep you posted.
Regards
Olivier

Hello I managed to compile libphidget22, version 1.6-20200306 on my old pi1B+ I can run HelloWorld linked against the lib with no issue. I wanted to run the networkserver, but when compiling libphidget22extra, same version, any program linked against that lib causes "illegal instruction" a...