Hi,

Any ideas or suggestions?

At the last months meeting I gave a somewhat impromptu presentation on the Linux Session Desktop Bus (D-Bus) being used for inter-process communication between client and server applications running on my laptop. I've now set up a Raspberry Pi to utilize the System D-Bus for the client / server applications. The Pi was using the latest Raspian release Debian 8 / Jessie, but a revision issue required upgrading to the testing release of Debian 9 / Stretch. Each of four server applications receives digital input pulses from its GPIO port. These server apps process their received data and each second they publish the data over the System D-Bus. A GUI client app subscribes to receive the published data from all four servers and displays the received information. The GUI client also performs method calls to each server to control the server and obtain additional data. The server apps are under the control of systemd and this automatically launches them on each reboot of the Pi. Although systemd runs them as root, their files reside in local folders to simplify editing changes to any of these server apps. Being under systemd/root control means that the server apps continue running when all users have logged out. The GUI client is a locally run application that may be started and stopped independent of the servers. If this is of interest then I'd be happy to present it at the next Monday's meeting. My presentation would be less than an hour. Thus there would be time for other presenters. cheers, Ian.