PiThermostat

Central heating system and/or Hot water system using a Raspberry Pi and optionally an LCD touchscreen. This project requires at least one TMP102 to make a thermostat. Integrates with Google calendar or Django Schedule to find required temperature. Works with one or two Shelly Relays to make a complete boiler control system.

The file structure of this project is as follows:

This directory - Python scripts to move to /usr/local/bin
utilities - useful associated scripts, but may not be required in all cases.
init - init scripts to be moved to /etc/init.d/
icons - graphics used by thermostat_gui.py. Can be moved, but icon_dir in thermostat_gui.py will need updating.
bin - main utilities for running thermostat.
utilities/433PlanB - to be used in the event of redis/thermostat_gui.py dying.

Install i2c using raspi-config

sudo raspi-config

Select Advanced mode, enable i2c and then reboot

Most of the Work below can now be performed using make:

make install

The summary of all events in the calendar should be of the form

 Temp=20.0

If using a Water calendar, then this should be off the form Water=On or Water=Off

Note that Django-Schedule has supplanted Google Calendar as the default. Uncomment line 88 if you wish to use Google Calendar.

The scripts to copy to /usr/local/bin are as follows:

| Script | Description | | ------------- | ------------- | | call_433.py | Makes redis calls to / from the redis server which maintains temperature states/ runs boiler. | | google_calendar.py | Grabs current temperature required from Google Calendar. | | processcalendar.py | Deprecated. Was used with django-schedule and is left here for future reference. | | thermostat_gui.py | Pygame binary to display data on screen and call all other libraries. | | calculate_temps.py | Pull in the data from the temperature sensors and calculates an internal and external mean |

Apache is protected by a username/password set in /etc/apache2/.htpasswd. This defaults to hotf/hotf.

Using Weather (optional)

Uses weather-util to retrieve weather info:

sudo apt-get install weather-util

Edit retreive_weather.sh (it is currently set to Leeds/Bradford airport):

sudo cp utilities/retrieve_weather.sh /usr/local/bin/
sudo cp utilities/parse_weather.py /usr/local/bin/
sudo chmod a+x /usr/local/bin/retrieve_weather.sh

crontab -e

Add a line similar to the following to retrieve the weather for your location

13 0,6,12,18 * * * /usr/local/bin/retrieve_weather.sh

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Using BME2x0 temperature sensor instead of a TMP102

Copy the file utilities/bmx280.py to /usr/local/bin/redis_sensor.py and restart the daemon:

cp utilities/bmx280.py /usr/local/bin/redis_sensor.py

systemctl disable redis_sensor --now
systemctl enable redis_sensor_bmx280.service --now
systemctl status redis_sensors_bmx280
● redis_sensor_bmx280.service - Read from BMX280 and feed result into redis
     Loaded: loaded (/etc/systemd/system/redis_sensor_bmx280.service; enabled; preset: enabled)
     Active: active (running) since Sun 2025-06-01 10:56:13 BST; 8min ago
   Main PID: 1131 (redis_sensor.py)
      Tasks: 1 (limit: 3910)
        CPU: 477ms
     CGroup: /system.slice/redis_sensor_bmx280.service
             └─1131 /usr/bin/python3 /usr/local/bin/redis_sensor.py

Jun 01 10:56:13 hotf systemd[1]: Started redis_sensor_bmx280.service - Read from BMX280 and feed result into redis.