Report temperature from second rpi to HA?

Configuration
1

Hey guys.

I’ve got a couple of pi’s working away in my place. One is for my HA installation, the other is for a Pihole and pivpn server using DNScrypt. Unfortunately the the pihole machine is an original Pi, and can get a little warm so i like to keep an eye on it.

I was wondering whether i can periodically forward the temp/cpu usage from this machine to my HA dashboard so i can monitor it? Since it’s already got a Pihole running, and the pihole admin interface outputs the cpu temp, load and memory usage, I was wondering whether this would be a simple fix?

Cheers for any input!

2

Send MQTT message to HA with temp stats

1 Like
3

Thanks mate, that sounds a good route. I’ve never used MQTT, and having a look seems fairly complex to me, i’m sure i can get my head around it in time.

So do i need a broker on the RP1 as well as the HA machine?

Can you break it down so i know where i’m going? I guess i need to write a script to publish the temperature on the RP1, and then, do i have to send it to the HA, or does the HA MQTT scan it, or probe it etc?

4

HA has built in MQTT server OR you may install your own

Install mosquito on remote RPi and send message like
mosquitto_pub -t ‘sensor/remote/temp’ -m ‘83’

HA has component to receive the message

It is very easy

1 Like
5

Brilliant, thanks mate, i’m just reading up on the examples on HA. I’ve got the broker on HA working, so now playing with the remote Pi.

I appreciate your input, love learning something new, however trivial it may be!

6

I use two HA’s and I just ask one HA if I want to know something though its api.

binary_sensor:
  - platform: rest
    resource: http://192.168.x.xxx:8124/api/states/binary_sensor.xxxxxxx
    name: xxxxxxxxx
    value_template: '{{ value_json.state }}'
    scan_interval: 5
3 Likes
7

I have exactly the same scenario as you do, and this is the kind of script I have running as a cron job every 5 minutes on all PIs (except the one where HASS is installed):

#!/bin/bash
PATH=/bin:/usr/bin

# Get CPU Temperature in degrees celsius
VALUE=$( cat /sys/class/thermal/thermal_zone0/temp | awk -v FS=" " '{print $1/1000""}' | cut -c1-5 )

if [[ "$VALUE" == "" ]]
then
VALUE=0
fi

curl -X POST \
     -H "Content-Type: application/json" \
     -H "x-ha-access: PASSWORD" \
     -d '{"payload": "'"$VALUE"'", "topic": "rpi_name", "retain": "True"}' \
     http://IP:PORT/api/services/mqtt/publish > /dev/null 2>&1 &

exit 0

On the HASS config side, I have:

### RPi Temp Sensor ###
sensor:
  - platform: mqtt
    state_topic: "rpi_name"
    name: RPi Name
    unit_of_measurement: '°C'
    force_update: True

This way, every RPi you want, can send the data to HASS.

3 Likes
8

Thanks for this, i’ll have a crack tomorrow. It’s taken me a while to get mqtt working, seems it’s got issues with rasbian-stretch, but tldr, installed via aptitude and seems to be working finally.

So your x-ha-access: Password, is this the HA api password? And the IP/Port, is that the HA ip too? Just getting my head around it. Thanks!

9

Yes to all.

1 Like
10

How about adding a sensor to either configuration.yaml or sensors.yaml:

Sensor:
- platform: command_line
name: Pi Temp
command: “cat /sys/class/thermal/thermal_zone0/temp”
unit_of_measurement: “°C”
value_template: ‘{{ value | multiply(0.001) | round(1) }}’

11

But in addition to the password of HA do not you also need to specify the username and password of the broker and IDClient?
I always have this connection error:" socket error on client unknown".
Help me, please.