We dont call this article a tutorial since not all steps of the sensor settings would be explained. It might be the idea of this article to show the general panorama of the sensor installation on a Raspberry Pi under the Istsos framework that implements the SOS standard.

Istsos github page:

github.com/istSOS/istsos2

Video

The journal is divided on several parts

Physical setup

Please install the sensor as explained on the figures and photos

Source: https://people.utm.my/shaharil/ds18b20-sensor/

On a Raspbian terminal

When you install Raspian set the username to “istsos”

Import the package to read the temperature sensor

pip install python3-w1thermsensor

pip install python-dotenv

Enable access to GPIO pins

sudo raspi-config

3 Interface Options > I8 Remote GPIO > Yes

Enable the sensor overlay

You need to update your boot file.

sudo nano /boot/config.txt

Then at the end add the following

dtoverlay=w1-gpio, gpiopin=4

Save the file

Finally, reboot

sudo reboot

Get sensor id

cd /sys/bus/w1/devices

ls

Check the sensor id as 28-XXXXXXXXXXXX where the X.. is the sensor id

Under the folder /opt/istsos create a file tempInsertObservation.py

sudo mkdir /opt/istsos

sudo nano /opt/istsos/tempInsertObservation.py

Paste this code

#!/usr/bin/env python
# coding: utf-8

from requests.auth import HTTPBasicAuth
from requests.packages.urllib3.exceptions import InsecureRequestWarning
import requests, json, os
from datetime import datetime
from dotenv import load_dotenv
from dateutil.tz import tzlocal
from dotenv import load_dotenv
from w1thermsensor import W1ThermSensor, Sensor

sensor = W1ThermSensor(Sensor.DS18B20, '0000071dacba')

#create a file env.txt with 
#USER='XXXX'
#PASSWORD='XXXX'
load_dotenv('/opt/istsos/env.txt')
user = os.getenv('ISTSOSUSER')
password = os.getenv('ISTSOSPASSWORD')

requests.packages.urllib3.disable_warnings(InsecureRequestWarning)

auth = HTTPBasicAuth(user, password)
url = 'https://apps.hatarilabs.com/istsos'
service = 'temperature'
procedure = 'genericSensor'
off = 'tempnetwork'

# Requesting a describe sensor mainly to store the assignedSensorId
resProcedure = requests.get(
    '%s/wa/istsos/services/%s/procedures/%s' % (
        url, service, procedure), auth=auth)
print(resProcedure)
procedureData = resProcedure.json()['data']

# Preparing "io" object to send
observedProperties = requests.get(
    '%s/wa/istsos/services/%s/operations/getobservation/offerings/'
    '%s/procedures/%s/observedproperties/:/eventtime/last' % (
        url, service, off, procedure),
    params={
        "qualityIndex": "False"
    }, auth=auth)

io = {
    "AssignedSensorId": procedureData['assignedSensorId'],
    "ForceInsert": "true",
    "Observation": observedProperties.json()['data'][0]
}

#humidity, temperature = Adafruit_DHT.read_retry(DHT_SENSOR, DHT_PIN)
temperature = sensor.get_temperature()
print("Recorded temperature of %s celsius" % temperature)

eventtime = datetime.now(tzlocal())

io["Observation"]['samplingTime'] = {
                    "beginPosition": eventtime.isoformat(),
                    "endPosition": eventtime.isoformat()
                }

ob = [eventtime.isoformat(),str(temperature)]

io["Observation"]['result']['DataArray']['values'] = [ob]

resInsert = requests.post('%s/wa/istsos/services/%s/operations/insertobservation'%(url,service),
                    data=json.dumps(io), auth=auth)

Define a cron job:

crontab -e

Add the following line:

* * * * * /usr/bin/python /opt/istsos/tempInsertObservation.py

Run the command once and check that a record has been made:

/usr/bin/python /opt/istsos/tempInsertObservation.py

Check if the cronjob is running:

sudo tail -100 /var/log/syslog

On another computer

Retrieve the output data as pandas dataframe with this Ipython notebook:

from requests.auth import HTTPBasicAuth
from requests.packages.urllib3.exceptions import InsecureRequestWarning
import matplotlib.pyplot as plt
import requests, json, os
from dotenv import load_dotenv
import pandas as pd

requests.packages.urllib3.disable_warnings(InsecureRequestWarning)

#create a file envViewer.txt with 
#USER='XXXX'
#PASSWORD='XXXX'
load_dotenv('envViewer.txt')
user = os.getenv('ISTSOSUSER')
password = os.getenv('ISTSOSPASSWORD')

auth = HTTPBasicAuth(user, password)

url = 'https://apps.hatarilabs.com/istsos'
service = 'temperature'
procedure = 'genericSensor'
off = 'tempnetwork'

beginTime = "2023-06-01T00:00:00-05:00"
endTime = "2023-06-01T20:00:00-05:00"
# Preparing "io" object to send
observedProperties = requests.get(
    '%s/wa/istsos/services/%s/operations/getobservation/offerings/'
    '%s/procedures/%s/observedproperties/:/eventtime/%s/%s' % (
        url, service, off, procedure,beginTime,endTime),
    params={
        "qualityIndex": "False"
    }, auth=auth)

observedList = observedProperties.json()['data'][0]['result']['DataArray']['values']

observedList[:5]

[['2023-06-01T10:49:04.650563-05:00', 23.625],
 ['2023-06-01T10:50:04.170496-05:00', 23.625],
 ['2023-06-01T10:51:05.050523-05:00', 30.5],
 ['2023-06-01T10:52:04.490570-05:00', 29.125],
 ['2023-06-01T10:53:04.810532-05:00', 28.0]]

observedDf = pd.DataFrame(columns=['Date','Temp'])
observedDf

	Date	Temp

observedDf['Date'] = pd.to_datetime([i[0] for i in observedList])
observedDf['Temp'] = [i[1] for i in observedList]
observedDf = observedDf.set_index('Date')
observedDf.head()

	Temp
Date
2023-06-01 10:49:04.650563-05:00	23.625
2023-06-01 10:50:04.170496-05:00	23.625
2023-06-01 10:51:05.050523-05:00	30.500
2023-06-01 10:52:04.490570-05:00	29.125
2023-06-01 10:53:04.810532-05:00	28.000