Monitor remote PI CPU temp

yocke · February 25, 2017, 1:56pm

Hi,

So i want to monitor the CPU temp on a RPi i have.
I looked in to Glances but no dice.
Looked throw the forum but no luck there.
Is there any one who have solved this or have some tips on how i can move forward?

jjmontesl · February 25, 2017, 2:50pm

If home assistant is running on the Raspberry Pi, I use this:

sensor:

  - platform: command_line
    name: CPU Temp
    command: "/bin/cat /sys/class/thermal/thermal_zone0/temp"
    unit_of_measurement: "ºC"
    value_template: '{{ value | multiply(0.001) }}'

  - platform: systemmonitor
    resources:
    - type: disk_use_percent
      arg: /
    - type: memory_free
    - type: memory_use_percent
    - type: processor_use
    - type: since_last_boot
    #- type: network_in
    #  arg: eth0
    #- type: network_out
    #  arg: eth0

I put this in a file `packages/dev_pi.yaml" or similar, and include the package from the main configuration.

Then I havea group:

dev_pi:
  name: Pi
  entities:
    - sensor.cpu_use
    - sensor.cpu_temp
    - sensor.disk_use_
    #- sensor.disk_use_home
    - sensor.ram_free
    - sensor.ram_use_percent
    - sensor.since_last_boot

PtP · February 25, 2017, 11:07pm

@jjmontesl is on to something.

You can install HA on the pi and add the example of how to monitor the CPU. You can remove the frontend, logbook , and history from this instance.

Then on your main HA instance you can create a command line sensor that uses an API call to get the information from the 2nd RPi.

May be a bit much though.

yocke · February 26, 2017, 10:26am

Hi,

Thanks for your input.

No, HA is not running on this PI.
The one i would like to monitor is running kodi and i wanted to keep an eye on the temp.

No suggestions there?

yocke · February 26, 2017, 10:27am

Thanks for the suggestion but as you say, it is a bit much to just get the temp.

Must be a better way of doing this

yocke · February 26, 2017, 10:57am

So i though of something that i don´t know will work but i ask you anyway

If i run a bash script that connect to the remote host and check the temp and then write this to a file that it the copy to HA and then i run a command_line to read the file?

Is this possible or am i just way way off?

jjmontesl · February 26, 2017, 1:32pm

For a quick value like that, maybe you can use a command line sensor, and ssh into the second raspberry to run the very same command.

I’d:

Create a dedicated user for Hass in the second raspberry (sudo adduser homeassistant)
From the first raspberry, copy ssh keys and log in using the home assistant user that runs in the first pi: ssh-copy-id homeassistant@kodipi.
Then for the sensor command use something like ssh homeassistant@kodipi "/bin/cat /sys/class/thermal/thermal_zone0/temp"

I’ll be looking into monitoring temperature with Glance (in my case for my laptop), not sure I’ll make it today. Hopefully the approach above works for you.

yocke · February 28, 2017, 4:48am

Hi, i tried you approach and i’m sorry to say that it did not work.
Just get a - in the bubble were the temp should be

jjmontesl · February 28, 2017, 7:53pm

Try the chain of commands.

On the kodipi, using your homeassistant user, try:

sudo su - homeassistant
/bin/cat /sys/class/thermal/thermal_zone0/temp

On the first raspberry, try:

sudo su - your_first_raspberry_ha_user
homeassistant@kodipi “/bin/cat /sys/class/thermal/thermal_zone0/temp”

And let us know the results.

yocke · March 1, 2017, 5:07am

Success!

Thanks so much for your help!

So, just for reference and if someone else is trying to do the same in the future i will write down the steps

Create the homeassistant user on the second RPI, sudo adduser homeassistant
I generated RSA keys, and copied them from HA to the second RPI, was using this site, http://www.thegeekstuff.com/2008/11/3-steps-to-perform-ssh-login-without-password-using-ssh-keygen-ssh-copy-id
If i didn’t do this step is asked for password when i try to log on to the Second RPI from HA.
Added this to my configuration.yaml on HA:

platform: command_line
name: Kodi CPU Temperature
command: ssh “Second RPI IP” “cat /sys/class/thermal/thermal_zone0/temp”
unit_of_measurement: “°C”
value_template: ‘{{ value | multiply(0.001) }}’

And that´s about it to get it to read the temp of the second RPI.

Thanks again for your help, could not have done this without you

simo26246 · November 16, 2017, 5:20am

For anyone following along with this later on - if you’re trying to do this, make sure you add the ssh keys from INSIDE your HA virtual environment (ie, follow the update commands). That’s where I was being tripped up!

Lentron · December 11, 2017, 11:35am

This is a great sample, thank you!
I’ve got a question in addition to this post:

what if i’d like so change the format of “type: since_last_boot”?
in this sample it wil result in “hh-mm-ss.xxxxxxx”

can i change this to “hh-mm-ss”?
or perhaps set conditions: if < 1 day --> “hh-mm” , if < 1 day --> “dd”, if < 30 days --> “mm-dd” ?

crider17 · July 12, 2020, 5:17am

I know this is an old thread but I’m having trouble using this to grab the CPU temp on a remote Pi 4. I created the RSA keys and set them up successfully. Added code to my configuration.yaml:

platform: command_line
name: Driveway CAM temp
command: ssh “remote_IP” “cat /sys/class/thermal/thermal_zone0/temp”
unit_of_measurement: “°C”
value_template: ‘{{ value | multiply(0.001) | round(1) }}’

The card just shows “unknown” for the value. I’ve experimented with several different command formats (single/double quotes, quoting different parts/all of command, etc.) Nothing changes.

I’m able to SSH to my remote pi w/o typing a PW. Also, this command ran from the terminal on my HA Pi 4 seems to work:
$ssh remote_IP cat /sys/class/thermal/thermal_zone0/temp
It returns:
Welcome to remote_RPi_name
46251

Any ideas what I’m doing wrong?

Thanks.

Troon · July 12, 2020, 7:49am

I wonder if the welcome message is confusing things. Try changing the command to:

platform: command_line
name: Driveway CAM temp
command: ssh "remote_IP" "cat /sys/class/thermal/thermal_zone0/temp | tail -n 1"
unit_of_measurement: "°C"
value_template: '{{ value | multiply(0.001) | round(1) }}'

(and for future reference, please format your code snippets correctly, surrounded by three backticks)

crider17 · July 12, 2020, 11:17am

Troon -

Thank you for your reply and the tip on formatting my code.

That did not work. Same result. I initially thought the same so after some research I added a .hushlogin file to /home but that did not seem to do anything. After adding your suggestion to my yaml the card still showed “uknown”. To test, from my HA terminal I executed:

ssh *remote_IP* cat /sys/class/thermal/thermal_zone0/temp | tail -n 1 > output.txt
AND
ssh *remote_IP* cat /sys/class/thermal/thermal_zone0/temp > output.txt

In both cases it does not appear to have the welcome message stored in the output.txt:

*ssh commands*
Welcome to *remote_RPi_name*!
$ cat output.txt
46738

So, it would seem that while I am seeing the welcome message when I test from my HA Pi, it is not included in the returned cat value.

Any other ideas? Thanks again for your help.

duceduc · August 15, 2020, 1:49am

How to create and or add the key to the rpi that has Hassio with docker installed?

andynbaker · August 15, 2020, 11:15pm

Hey guys, i ended up ditching my ssh command line sensor for cpu temp as the value is included when running the system_sensors script. I’m using this now instead of glances and have had no issues so far. This script publishes the following values to MQTT:

CPU usage
CPU temperature
Disk usage
Memory usage
Power status of the RPI
Last boot
Swap usage
Wifi signal strength
Amount of upgrades pending
Disk usage of external drives

If you use the MQTT add-on, the raspberry pi will be discovered automatically and added as a device. This is all coming over now by way of the script. I owe the dev a beer:

Thomas_Gregg · October 3, 2020, 10:42pm

@duceduc I have the same question. Could you figure it out?

duceduc · October 3, 2020, 11:00pm

I’ve never got the ssh key sorted out. But I think you can generate the key using puttygen. To add the key to Ha, you will need to install ssh & web terminal add-on and cd to .ssh and drop the key in there.

I found another solution and it has worked for me. I install the sensor.ssh and place it in the custom_components folder in HA. Create a dev_rpi.yaml and add to your package folder.

dev_rpi.yaml (Note: the first sensor is HA and is local. The rest is from different RPIs)

## Uses the SSH Sensor from HAC
## https://github.com/custom-components/sensor.ssh
sensor:
# Hassio CPU
  - platform: command_line
    name: HA CPU Temperature
    command: "cat /sys/class/thermal/thermal_zone0/temp"
    unit_of_measurement: "°C"
    value_template: '{{ value | multiply(0.001) | round(1) }}'
# ns1 CPU
  - platform: ssh
    host: 192.168.1.10
    username: ns1
    password: !secret rpi_pass
    name: NS1 CPU Temperature
    command: cat /sys/class/thermal/thermal_zone0/temp
    unit_of_measurement: "°C"
    value_template: >-
      {%- set line = value.split("\r\n") -%}
      {{ (line[1]|int / 1000) | round(1) }}
# ws1 CPU
  - platform: ssh
    host: 192.168.1.15
    username: ws1
    password: !secret rpi_pass
    name: WS1 CPU Temperature
    command: cat /sys/class/thermal/thermal_zone0/temp
    unit_of_measurement: "°C"
    value_template: >-
      {%- set line = value.split("\r\n") -%}
      {{ (line[1]|int / 1000) | round(1) }}
# ps1 CPU
  - platform: ssh
    host: 192.168.1.25
    username: ps1
    password: !secret rpi_pass
    name: PS1 CPU Temperature
    command: cat /sys/class/thermal/thermal_zone0/temp
    unit_of_measurement: "°C"
    value_template: >-
      {%- set line = value.split("\r\n") -%}
      {{ (line[1]|int / 1000) | round(1) }}

Thomas_Gregg · October 4, 2020, 8:15am

Thanks so much. That works great!