1

I installed octoprint to my raspberry pi earlier this year in order to control my 3d printers.

I've been able to make the pi control 2 printers at once using octoprint. Also I've added a second camera (USB) to view the second printer. I managed to find a way to start the second camera and edit octoprint to see the difference in the two.

My only problem is every time I start my raspberry pi up again I have to change to different a working directory:

cd ~/mjpg-streamer

then this to start the second camera:

./mjpg_streamer -i "./input_raspicam.so -fps 5" -o "./output_http.so -p 8090"&

I want to be able to write a script to start the camera on boot so I don't have to ssh to my raspberry, login, and send the commands every day. I've found a lot about writing boot scripts but nothing about changing the working directory inside it.

I've been using this to write start scripts (unsuccessfully):

sudo nano /etc/init.d/startsecondcamera
2

Make the startup script do the cd before running mjpg_streamer, just like you're doing manually:

#!/bin/sh

cd /home/geilisa/mjpg-streamer
./mjpg_streamer -i "./input_raspicam.so -fps 5" -o "./output_http.so -p 8090"

This is assuming that your home directory is /home/geilisa.

You can't use ~ in the script since it's likely run by root. If running the utility as root is an issue, use sudo -u gelisia ./mjpg_streamer ... in the script to run it as user gelisia instead.


An alternative is to add a cron job that runs at boot:

@reboot cd /home/geilisa/mjpg-streamer && ./mjpg_streamer -i "./input_raspicam.so -fps 5" -o "./output_http.so -p 8090"

Add this in your crontab by using the command crontab -e. This will open an editor with your crontab (possibly an empty file). Add the above line, save, and exit.

Most cron's that I know of allows for using @reboot (and @hourly, @daily etc.) instead of the five job scheduling columns that usually goes before the actual command.

  • Thank you so much the cron job worked! I probably just messed up the script more, but that is okay. Thank you so much! – Geilisa Almodovar Sep 15 '17 at 16:49
  • @GeilisaAlmodovar Good! If this solves your issue, please consider accepting the answer. – Kusalananda Sep 15 '17 at 17:08

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