this script does two things: reading temperature and humidity from a dht22 connected to your pi as well as writing it to a google spreadsheet. if used with cron this can e done on schedule.
this is described here (https://github.com/adafruit/Adafruit_Python_DHT/blob/master/examples/AdafruitDHT.py)
a basic authentification with readonly is described here and was used as template for this project (https://developers.google.com/sheets/api/quickstart/python) tbh: the authentification on the raspberry is a bit painful, because you have to browser authenticate on the raspberry, which is very slow. be brave! (https://developers.google.com/sheets/api/reference/rest/v4/spreadsheets.values/append) this shows how values can be appended to a spreadsheet with using the full spreadsheet permission scope.
it took me a while to figure out that the token.pickle file needed to be deleted for switching from readonly to full spreadsheet scope. this is because it contained the permissions associated with readonly. if the script does not find the token.pickle file, you will have to re authenticate again, the new
pickle will will then contain the new role. see (https://stackoverflow.com/questions/38534801/google-spreadsheet-api-request-had-insufficient-authentication-scopes)
the credentials.json has to be in the root folder of the repo as well. you can obtain them via the quickstart url above.
for every 5 minutes, this might wat you want:
*/5 * * * * cd /home/pi/devel/dht22_to_spreadsheet; /usr/bin/python3 main.py >> /home/pi/devel/log.log 2>&1
the cd is needed for the credentials and token file to be found..