Scheduling ebrow --rmob in Linux

[Christopher Holt]

I have now had Echoes 0.61-1 running on my Ubuntu 24.04 LTS system for several days. It is working well and detecting meteor forward scatter reflections with good sensitivity. Ebrow 0.3 also runs well in a venv from a terminal and, using ebrow --rmob, it uploads the data to rmob.org.

I wanted to run ebrow --rmob hourly and attempted to do this using cron via a crontab entry. I was able to get ebrow to open under cron but it would not run properly. This seems to be because cron is for running background tasks rather than scripts that generate a graphical interface (GUI) such as ebrow. Ebrow was failing because it uses Maplotlib and could not find the qt5agg backend because it was running "headless" (or something like that!). I tried various fixes, such as setting DISPLAY to :0 and running within Xvfb but without success.

Instead, I found that, rather than use crontab, I could achieve hourly running of ebrow --rmob using the watch command:
watch -n 3600 /your/full/path/to/run_ebrow.sh

where run_ebrow.sh is my script for running ebrow --rmob in its venv.

I thought others might find this helpful.

[gmbertani]

Hi Christopher,

this is the crontab line I use in my GABB station, running Opensuse Linux Tumbleweed:

 20 * * * *      DISPLAY=localhost:0 nice /home/zot/.local/bin/ebrow --rmob --verbose

ebrow has been installed with pip and works nicely in this way and doesn't need a dedicated script but I remember at the beginning I faced your same problem with crontab.

After many attempts, at the end I solved by placing DISPLAY=localhost:0 before the command.

Thank you anyway for your alternative, you did well to point it out, I had never attempted to use watch

[Christopher Holt]

Thank you for sharing your crontab line. Including localhost appears to be the main difference. If I try again with crontab, I will try including that.

Meanwhile, watch continues to work well in my case. Had that not worked, I might have looked into making a systemd timer. Such is the joy of Linux: so many tools to choose from!