Raspberry Pi Forums

Posted: **Sun Mar 04, 2018 12:31 pm**

Hi everyone
New here using python. I have a PI hooked up to a RGB led matrix, and an Adafruit RGB Matrix HAT that has the clock built in.
I am running a couple of text scripts manually by just typing the sudo ./runtext.py or runtext1.py or runtext2.py etc. that runs a different text and I run the script at certain times in the day. This is because I use the display as a sign IE: Open, closed etc.

Is there a simple python script I could insert that would run script 1 say at 8am until 6:30 then run script 2 for 2 hrs then back to script 1 or another script or off etc using my HAT clock?
Any help would be appreciated and thank you in advance.

Posted: **Wed Mar 14, 2018 7:20 pm**

Sounds like you need the help of 'cron'.
'cron' is a system utility that can execute commands at scheduled times.
'crontab' is the program you use to define 'cron' tasks.

Check the man pages for more details

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man cron
man crontab
man 5 crontab

If you really need to run you scripts as root then use

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sudo crontab -e

The comments in the file will describe the format of the entries. You probably want to ad entries like

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# Run at 8:00 on weekdays
0 8 * * 1-5 /<path-to>/runtext.py
# Run at 6:30pm on weekdays
30 18 * * 1-5 /<path-to>/runtext1.py

Posted: **Thu Mar 15, 2018 12:48 am**

Thanks @ Jostle another small question how could I get it to start at say 8am and stop at 6:30 on the same day ? would I just add the cntrl C command (which stops the board) at a certain time ? if so I'm not really sure how to incorporate it ..Really appreciate the help

Posted: **Thu Mar 15, 2018 10:41 am**

I assume, from your question, that your scripts run continuously in a loop until killed.

If that is the case then I would just add a crontab entry to kill the running script.

So, if your first script is /home/pi/script1.py and you second script is /home/pi/script2.py, your crontab could look like this

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# Start script1.py at 8:00am on weekdays
0 8 * * 1-5 /home/pi/script1.py
# Kill script1.py at 6:30pm on weekdays
30 18 * * 1-5 pkill -f /home/pi/script1.py
# Start script2.py at 6:30pm on weekdays
30 18 * * 1-5 /home/pi/script2.py
# Kill script2.py at 8:30pm on weekdays
30 20 * * 1-5 pkill -f /home/pi/script2.py

Have a look at

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man pkill

for details of the options available for pkill.

Posted: **Thu Mar 15, 2018 11:35 am**

Thanks Again @Jostle what I actually do is run 1 script ex:=script1.py at 8am during wekkdays and do a (Ctrl + c ) at 6:30 as the Ctrl key +c stops the Leds from scrolling the message and on weekends another script Ex:script2.py with the Ctrl+c key to stop it at a certain time. Sorry If I'm not getting it so in my Kill crontab it would contain the keystrokes (Ctrl+c) or the kill instructions you gave me are understood by Pi as the same ? I normally do this all in the terminal window (which is always up on the PI) so really I just arrow up in the am and hit enter as this brings up the previous command and at 6:30 Ctrl+c to stop (not sure if I'm clear)

Posted: **Thu Mar 15, 2018 1:36 pm**

I found the schedule function nice and easy to use. Just include the code in your script. Check out the schedule documentation for other options

In the example below you can add an open and close event line for each day as required. The ShopOpen and ShopClosed functions will run once (1 time) when the appropriate time is reached.

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import time
import schedule

def ShopOpen():
    print "Shop Open"
    #Put your sign control for shop open here

def ShopClosed():
    print "Shop Closed"
    #Put your sign control for shop closed here

    
schedule.every().thursday.at("09:00").do(ShopOpen)
schedule.every().thursday.at("13:00").do(ShopClosed)

while True:
    schedule.run_pending()    # checks if the time matches the scheduled event
    time.sleep(1)

Posted: **Thu Mar 15, 2018 1:39 pm**

Thanks again @Jostle for your time and patience I will try that

Posted: **Fri Mar 16, 2018 1:51 am**

Thanks to rkn704 for the info on the schedule function in python.

All cron does is execute the commands in the crontab at the given times, just as if you had entered the same command in a terminal. The difference is that they are run in the background, rather than as a child process of the shell.

When you type (Ctrl + c ) in a terminal the shell sends a kill signal to the child process that is running in the foreground.
'pkill' is just a linux command that sends a kill signal to any process that matches the given command name. So 'pkill' can be used to terminate any process even if it is running in the background, that is, not a child of a shell.

I suggest you try running your script in a terminal and running (based on your original example)

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sudo pkill -f ./runtext.py

from a second terminal to see how it works.

You should be able to get the results you need from 'cron' using the example I gave, with suitable changes to the times and commands.

Posted: **Fri Mar 16, 2018 12:16 pm**

Thats right I missed that Thank you rkn704 for that and thank you for your time Jostle

Posted: **Tue Mar 12, 2019 4:29 pm**

ok new question if anyone can help please do

I have a text script at location> /home/pi/rpi-rgb-led-matrix/bindings/python/samples called open green.py. It runs a scrolling text on a RGB Matrix screen attached to my Pi
I can run it if I cd to that directory and run sudo./opengreen.py. it runs until I press CTRL-C to stop it

I want to use a cronjob to run this every day of the week Tue to Friday from 10:30am to 6:30pm then I want it to stop running and or have the choice to run another script till midnight (same path but called closedor.py).

So basically my display board would run the open green.py from 10:30 till 8:30pm then switch to closed till midnight then shut off by killing the script.

I've tried using sudo crontab -e to write the crontab at root and this is what I put in the file
# Edit this file to introduce tasks to be run by cron.
#
path=/home/pi/rpi-rgb-led-matrix/bindings/python/samples
30 10-20 * * 2-5 /home/pi/rpi-rgb-led-matrix/bindings/python/samples/opengreen.$
#crontab to run open sign

I'm assuming this will run at 10:30 till 8:30 Tuesday till Friday but you know what happens when you assume

But nothing happens ?? I do the reboot and I did the /etc/init.d/cron start it asks me for a password but again nothing

If I run the cron status I get

● cron.service - Regular background program processing daemon
Loaded: loaded (/lib/systemd/system/cron.service; enabled; vendor preset: enabled)
Active: active (running) since Tue 2019-03-12 12:39:07 ADT; 32min ago
Docs: man:cron(8)
Main PID: 304 (cron)
CGroup: /system.slice/cron.service
└─304 /usr/sbin/cron -f

Mar 12 13:04:01 raspberrypi CRON[1251]: pam_unix(cron:session): session clos… pi
Mar 12 13:06:01 raspberrypi CRON[1261]: pam_unix(cron:session): session open…=0)
Mar 12 13:06:01 raspberrypi CRON[1265]: (pi) CMD (/home/pi/CronJobs/RunACron…sh)
Mar 12 13:06:01 raspberrypi CRON[1261]: pam_unix(cron:session): session clos… pi
Mar 12 13:08:01 raspberrypi CRON[1280]: pam_unix(cron:session): session open…=0)
Mar 12 13:08:01 raspberrypi CRON[1284]: (pi) CMD (/home/pi/CronJobs/RunACron…sh)
Mar 12 13:08:01 raspberrypi CRON[1280]: pam_unix(cron:session): session clos… pi
Mar 12 13:10:01 raspberrypi CRON[1309]: pam_unix(cron:session): session open…=0)
Mar 12 13:10:01 raspberrypi CRON[1313]: (pi) CMD (/home/pi/CronJobs/RunACron…sh)
Mar 12 13:10:01 raspberrypi CRON[1309]: pam_unix(cron:session): session clos… pi
Hint: Some lines were ellipsized, use -l to show in full.

I have no idea what I'm doing wrong as I am real green at this any help at all would be appreciated I know I have to add more to get it to stop but I need help in first getting it to work?? Also as a side not Pkill does not seem to stop the script??

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