Category: Raspberry Pi

Raspberry Pi and Cron

After two days of attempting to get Cron to execute tasks (in this case shell scripts) on a Raspberry PI, I finally got it working.

I must have read at least three dozen sites and all my Raspberry Pi books in my attempts, nothing work..

Here are some of the suggestions I found.

This one states it will edit the users cron file:

pi@raspberry ~ $ crontab -e

This one states it will display all the users schedule cron tasks:

pi@raspberry ~ $ crontab -l

I did find these useful:

pi@raspberry ~ $ /etc/init.d/cron stop

pi@raspberry ~ $ /etc/init.d/cron start

pi@raspberry ~ $  /etc/init.d/cron restart

But none triggered my script to run, then in my notes, from a past project I found:

pi@raspberry ~ $  sudo nano /etc/crontab 

This allowed me to edit the system cron task list..

———————————————–

# /etc/crontab: system-wide crontab

# Unlike any other crontab you don’t have to run the `crontab’

# command to install the new version when you edit this file

# and files in /etc/cron.d. These files also have username fields,

# that none of the other crontabs do.

SHELL=/bin/sh

PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# m h dom mon dow user  command

17 *    * * *   root    cd / && run-parts –report /etc/cron.hourly

25 6    * * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts –repo$

47 6    * * 7   root    test -x /usr/sbin/anacron || ( cd / && run-parts –repo$

52 6    1 * *   root    test -x /usr/sbin/anacron || ( cd / && run-parts –repo$

10 * * * * pi cd /home/pi && ./jabberfix.sh

#

———————————————–

The last task, which runs at 10 minutes after the hour, for user pi, fixes my jabber connection.

Honestly, I have no clue what the other tasks are doing. More research! But I am very happy I now know how to add my own tasks to cron.

Enjoy

~David

 

 

WebIOPi – Wait through a couple versions before using!

Over the last couple of months I’ve been playing with a new web development system, WebIOPi.

Nice system, I’ve been reading wonderful projects that people have built using the system, most duplicates of the same projects. Temperature sensors and garage door opener.

I was able to get two temperature sensors up and working on the system, fairly easy. However when I attempted to develop my own ‘programs’ for the system, I ran into a minor, well major problem. No where in the documentation does it tell you where WebIOPi gets installed. So I search the Raspberry Pi for known code, find the html part but not the python. So I posted a question on the developers site, which was passed over with a boiler plate answer, that it wasn’t within the realm of the site. Oh! Great help. Great place to send students for help. Seems the program was written for engineers for engineers.

Feel free to check out their site above, read the instructions completely before trying to use this system. As easily as it installs, it not how easily it is to use!

Well, if your need extend beyond what they have fed you.

—–

My ‘out there’ goal was to have my raspberry pi send me a text message when a GPO changes state, basically an alarm. I have a remote connected to one GPO that it will monitor to arm and disarm the system (when disarmed don’t send text messages). Seems simple enough.

—–

Haven’t given up hope, still working on the project. Will post if I figure it out.

Franken – Wheezy

New project in the works. Push a Raspberry Pi to its breaking point.

We want to develop a mobile web server to host communications between both the PIFACE and Arduino that would grant access to users from either a closed network or the Internet. Act as a Mobile Media Server using PLEX, a Mobile WIFI hot spot, serving shared files and lastly a Mobile Web Camera using a Raspberry Pi Camera Module.

Specs so far:

  • Raspberry Pi Model B
  • 32 gb SIM for OS
  • 32 gb Thumb drive for media storage
  • PiFace control board
  • Arduino
  • WIFI
  • Camera

Planned Additions:

  • Plans to add Battery and Charger
  • Solar Battery Charger
  • LiveCode Server

Services Already working:

  • MySQL
  • Jabber – iChat
  • PHP – Web Server

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