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Monitor your laptop with fswebcam

Posted 03-20-2016 at 10:29 AM by ugjka
Updated 03-20-2016 at 10:42 AM by ugjka

This is a little tutorial on how to take a picture from the webcam with systemD timers every 15 minutes.

Install fswebcam a commandline utility for grabbing pics off the webcam

Create a script in /usr/local/bin/ called snap that grabs a pic and put date and time in the filename
Don't forget to chmod +x to make it executable

Code:

#/usr/local/bin/snap 
#!/bin/bash
_now=$(date +"%Y_%m_%d_%H_%M")
/usr/bin/fswebcam ${_now}.jpg

Check man fswebcam for info on how to customize the output. For example you might wanna add --no-banner if you don't need date and time banner on the picture. Also may wanna change the resolution of the pic, by default it is very small

Create a systemd timer that launches the script we created

You can modify these...
OnBootSec=1min Will run the script 1 minute after you boot your machine
OnUnitActiveSec=15min Specifies that we launch the script every 15 minutes afterwards

Code:

#/etc/systemd/system/webcamsnap.timer 
[Unit]
Description=Take a photo every 15 minutes

[Timer]
OnBootSec=1min
OnUnitActiveSec=15min

[Install]
WantedBy=timers.target

This is the accompanying service file that is launched when the timer is reached
Change your User= and Group= to whatever whatever user and group you wanna run this
Specify where to store the pictures with WorkingDirectory= (Your user and group need write rights)

Code:

#/etc/systemd/system/webcamsnap.service 
[Unit]
Description=Take a pic every 15minutes 

[Service]
Type=oneshot
ExecStart=/usr/local/bin/snap
User=ugjka
Group=users
WorkingDirectory=/home/ugjka/Images/WebCamSnap

Now you can enable the timer with systemctl enable webcamsnap.timer
Reboot! And you should have it working!

Check systemctl list-timers to see the timer status

Code:

$ systemctl list-timers 
NEXT                         LEFT      LAST                         PASSED       UNIT                         ACTIVATES
Sv 2016-03-20 17:11:51 EET   7min left Sv 2016-03-20 16:56:51 EET   7min ago     webcamsnap.timer             webcamsnap.service

That's it

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Comments

Clever
And instructive. Now I know how to set up a system service too...
Thanks
Melissa

Posted 03-20-2016 at 04:57 PM by ButterflyMelissa

	You can create a timelapse of your pics with this command Code: mencoder mf://*.jpg -mf fps=25:type=jpg -ovc x264 -x264encopts bitrate=3200:threads=2 -o outputfile.mp4 Example output: http://dl.ugjka.net/timelapse.webm
	Posted 03-24-2016 at 03:39 PM by ugjka