Rule to control a script on second raspberry with arguments

---

Hi guys,
i build a flower watering pump system on my balcony with a raspberry pi. The pi is connected to my wifi. I need a rule (shell execute) to start the script on the pi. Important is that i want to handover an interger value to the script. The integer value is the time in seconds how long the relay stay switched on.
May you can help me?

Cheers
dk00000

@dk00000

hey dk,

i’ve done similar to turn on my webcam on secondary pi via ssh

if $plantsoil = "No" for 10 seconds then execute "sshpass -p '<pipassword>' ssh -o StrictHostKeyChecking=no <piuser>@<remote-pi-ip> 'sudo ./home/pi/watering.sh'" and pushbullet title:"Plant has just been poured" and execute "curl <pimaticuser>:<pimaticpassword>@localhost/api/device/plantsoil/changePresenceTo?presence=true >/dev/null 2>&1 || true"

Edit:

the sh-script on the second pi with the wateringpumprelay on gpio4 could be like this:

#!/bin/bash
gpio mode 4 out
gpio write 4 1
sleep $1
gpio write 4 0

and run with ./soil.sh 1 for watering one second ./soil.sh 2 for 2 seconds…

hope this helps as example

@dk00000, consider using MQTT. https://forum.pimatic.org/topic/1495/sending-data-from-one-pimatic-to-another-over-mqtt.

@xCite86

Sorry i forgot to say that i use a python script on the second py to control the relay. It works like a charm. The problem is just: how to handover a argument to this script and how to start the script via the first pi with pimatic.
In your answer i can find a way to start the script on the second pi. So far so good. How can i handover the integer value? Found via google sys.argv. Do you have some expirience?
Thanks

I would simply let the first Pimatic update some values on the second pi. The second pi will notice the updated variable(s) and execute the local script with the vlaues from the variables. In the same rule to detect change of variables and executing the script you set the variables empty.
Updating the variables from one pi to the other can be done by executing curl with a shell-execute command to update the variable with the API.

@dk00000 said:

Sorry i forgot to say that i use a python script

See post from @xCite86 which should also work with python. Make sure your python script is executable and your script is able to handle command line parameters.

@dk00000

i didn’t try to get the parameter values ( the “1” of python soil.py 1) into the pythonscript, but via sh script should work as the same to control the gpio`s and switch on the relais for x seconds (x was the value as example)

approximately in the middle of the rule

if $plantsoil = "No" for 10 seconds then execute "sshpass -p '<pipassword>' ssh -o StrictHostKeyChecking=no <piuser>@<remote-pi-ip> 'sudo ./home/pi/watering.sh'" and pushbullet title:"Plant has just been poured" and execute "curl <pimaticuser>:<pimaticpassword>@localhost/api/device/plantsoil/changePresenceTo?presence=true >/dev/null 2>&1 || true"

was sudo ./home/pi/watering.sh which you could replace with sudo python <yourscript.py>

maybe you have to sudo apt-get install sshpass before

@all
Thanks for your help

@dk00000 said:

How can i handover the integer value? Found via google sys.argv. Do you have some expirience?

Don’t know if still needed, but here are some lines how to handle cmd params in python

import sys

arg1 = sys.argv[1]
arg2 = sys.argv[2]

print arg1, arg2

or if you need an int value

import sys

num1 = int(sys.argv[1])
num1 += 1

print num1

@dk00000 said:

The integer value is the time in seconds how long the relay stay switched on.

and is it possible to use a pimatic variable in the execute part of the rule? something like that:

if 10:00 then execute "sshpass -p '<pipassword>' ssh -o StrictHostKeyChecking=no <piuser>@<remote-pi-ip> 'sudo ./home/pi/watering.py $duration' " 

if it is a hot day the duration is longer that on cold days (because my plants need on hot days more water) but this i want to control i another rule

Short question, why not simply install pimatic on the remote machine and use the API (HTTP via curl)? This way you have many options of controlling the remote machine via triggering rules or changing dummy devices/variables. In addition the remote machine would then also have a convenient webinterface and you could also use pimatic to create rules instead of using scripts.

@dk00000 said:

and is it possible to use a pimatic variable in the execute part of the rule? something like that:

Yes, your oulined example rule should work. Pimatic variables are even expanded as part of single quoted text.

@thex said:

Short question, why not simply install pimatic on the remote machine and use the API

Another option is to use MQTT as @wutu pointed out earlier. Anyhow,
I wouldn’t say setting up the one or the other solution is simpler than the others, but yes, setting up a pimatic slave offers more flexibility. Btw, it would be great of someone takes the initiative of writing a tutorial on setting up secondary pimatic server with examples.

@mwittig said:

Btw, it would be great of someone takes the initiative of writing a tutorial on setting up secondary pimatic server with examples.

I was thinking more that we should have a pimatic slave plugin which connects to the other pimatic instance via websockets and one could simply ad a device like:

{ 
  "id": "pimatic-instance-two-switch",
  "class": "PimaticRemoteSwitch", 
  "name": "My fancy remote switch",
  "host": "my.second.pimatic.instance.ip",
  "user": "username",
  "port": 443,
  "ssl": true,
  "password": "password"
}

by the way are there more plugin instances possible? Then one could have multiple instances instead of defining host/port/ssl/usernam/password for each device.

@thex said:

I was thinking more that we should have a pimatic slave plugin

Agree, this would be nice. Give me a couple of days for a proof of concept. EDIT: With pimatic 0.9 such a plugin can automatically discover available remote devices. So, setting the whole thing up will become a lot easier

Great! I’m so looking forward to 0.9 that I’m thinking about updating my productive system from github ^^

I have created a proof of concept project, called pimatic-remote, which implements a remote switch. In the coming weeks I am planning extend that and to combine it with Sweetpi’s ealier work on pimatic-peer. As said ealier, with pimatic 0.9 it’ll be possible to auto-discover remote devices which simplifies the setup a lot.

Another approach I am investigating is to automatically mirror the remote devices using a generic replica device similar to the RemoteDevice of pimatic-peer.

https://github.com/mwittig/pimatic-remote

Sonds great!
Is there any documentation on autodiscovery yet? would be great for the netatmo plugin I’m working on

@thex said:

Is there any documentation on autodiscovery yet?

See section Device auto-discovery at https://github.com/pimatic/pimatic/issues/859.

not to forget to show you my flower pump tower:

like last time i recycled (upcycled ) an old breadcase (case-cover is not on the pics) from the kids, just to make it really waterproof.

at the moment there is just a relay (with the pump) and a temperature sensor installed.

next step is an ultrasonic sensor to know how much water is in the pipe.

the pipe has a diameter of 25cm.
so i can store round about 50 liter. (manual refill). but its enough to go on vacation for two weeks

if you have more ideas (there are a lot of free gpios) or questions, please write.

happy tinkering.

dk00000