Pi Temperature Dashboard

Richard Davey
Last updated on 2021-02-06
Code

DS18B10 temperature sensing on a Raspberry Pi, and Darksky weather posting to an Adafruit IO dashboard

Full code and instructions are here

Prerequisites

  • Raspberry Pi
  • Python 3.x
    • Adafruit_IO python module
    • sqlite3 python module
  • DS18B10 thermoprobe and 4.7K Ohm current limiting resistor (or DS18B20 with a code tweak)
  • Adafruit IO account (io.adafruit.com) with the following feeds created (or rename and tweak the code)
    • ‘temperature-time-series’
    • ‘current-temperature’
    • ‘current-weather’
    • ‘high-temp’
    • ‘low-temp’
    • ‘status’
  • Optional Dark Sky weather account (https://darksky.net/dev)

Note, Dark Sky are no longer accepting new accounts but it is easy to replace with another weather API or remove altogether.

Preparation

Wire up the DS18B 1-wire device according to these instructions.

From the Raspberry Pi terminal run:

apt install sqlite3 nohup
pip install adafruit-io
pip install sqlite3
raspi-config
# Enable 1-wire devices using the advanced menu option

API keys

Create a file called api.txt in the git folder with a key, value pair per line separated by a space. It should have the following keys in any order (fill in missing values denoted by *):

DS_URL https://api.darksky.net/forecast
DS_KEY *
IO_USER *
IO_KEY *

This keeps API secrets separate from code. Consider changing permissions on this file for further security.

Database

Once sqlite3 is installed a database must be created and a table created within it with the following structure. Run the following from the terminal.

sqlite3 temperature.db
#>> from within sqlite...
create table conservatory(
  date char(50),
  time char(50),
  conservatory_temp real,
  darksky_current_temp real)
);
.quit # Quits sqlite3

Running

From the terminal in the git folder run chmod +x temp_dashboard.py to allow the python file to execute. Then run nohup temp_dashboard.py & to run the script detached from the terminal. The terminal can be closed without interrupting the script.

Autorun from boot

Alternatively add the following line to crontab in order to run at startup:

crontab -e
#> Within cron...
@reboot sleep 30 && /usr/bin/python3 /home/pi/python/temperature_dashboard/temp_dashboard.py &

Replace the path to folder with your own. @reboot triggers the command to run at boot; sleep 30 ensures that the required system daemons and services are up before the script requires them.

An alternative method is to use systemd. This link explains how to easily set it up.

Acknowledgements

For Adafruit IO connections https://github.com/adafruit/Adafruit_IO_Python

For DS18B code https://learn.adafruit.com/adafruits-raspberry-pi-lesson-11-ds18b20-temperature-sensing

Python IoT

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