#Thermostat

A simple thermostat for Raspberry Pi using DS18B20 and Flask

##Features

• A calendar for scheduling temperatures
• A performance graph showing how often the heater is switched on/off
• Nice big temperature display
• Suitable for electric heaters

As a bonus, you can control other appliances if your relay board has more than one channel.

##Design

Two things are connected to the GPIO of the RPi:

• A relay board - controlled via the RPi.GPIO library
• A DS18B20 thermometer

The engine.py contains all the logic for controlling the relays

##Motivation

As an international student, life quality sucks in the UK when the heater has no built-in thermostat. Since I'm a computer science student, I decided to build my own with a Raspberry Pi, relay board, and a DS18B20 thermometer.

##How to build

(Assuming you're doing this on the RPi running Raspbian , I've never tested the following on any other platform)

First, install Flask:

sudo pip install Flask

then simply run:

python interface.py

Note that you might need to modify the following files to match your setup:

• ds18b20.py - the constant DEFAULT_DS18B20_DIR needs to point to your DS18B20
• hal.py - the constant MAPPING needs to modified to match your relay board setup. In my case, it's a homemade 3 socket extension cord that looked like this:

And yes, the extension is bought from poundland :)

DS18B20 setup

There are several tutorials on this topic to help you get your DS18B20 up and running.

##TODO

• Deleting scheduled temperature changes on the calendar clears the entire calendar
• Add moisture sensing