The Blog of Ian Mercer.

Home Automation Systems as a Graph

Cover Image for Home Automation Systems as a Graph

Originally my home automation system was constructed as a tree: The house contains Floors, Floors contain Rooms, Rooms contain lights and sensors. That worked quite well for a number of years but there was always the issue of doors. Which room is a door in? An easy answer was to put it in both rooms, but now collections of doors like 'Interior Doors' had two copies of every door, whenever one door closed another one closed too!

Since then I've been migrating to a directed graph instead of a tree. The sole relationship used in the tree (representing 'contains') is being replaced with a variety of relationships like 'connected to', 'open to', 'audible from', 'visible from', 'above', 'below', ... that can express more interesting facts about the house.

This complicates the display of the house in the web view. Instead of traversing a tree it needs to perform a breadth-first search of the graph level-by-level using some relationship types but not others. It also complicates navigation as the breadcrumb bar needs to represent the shortest path back up the tree, not necessarily the one you followed to get here.

At this point I didn't have a way to visualize the graph, but recently I connected the graph up to an API and added another page to the Angular.js application for the house. This new page uses d3.js and webcola to render a force-directed graph layout. You can see some of the results here.

Zoomed in view of graph

As you can see the system is fairly complex. Currently this graph is showing both physical devices and logical devices. I plan to add an option to show just one or the other.

Related Stories

Cover Image for Home Automation

Home Automation

I've been working on home automation for over 15 years and I'm close to achieving my goal which is a house that understands where everyone is at all times, can predict where you are going next and can control lighting, heating and other systems without you having to do or say anything. That's a true "smart home".

Ian Mercer
Ian Mercer
Cover Image for Digital Twins are never identical

Digital Twins are never identical

Digital Twin are an online representation of a real world object, a copy of its properties in the digital world and a way to send updated and commands to it. In effect I've been making them for years but now they have a trendy name.

Ian Mercer
Ian Mercer
Cover Image for Home Automation Sensors

Home Automation Sensors

An overview of the many sensors I've experimented with for home automation including my favorite under-floor strain gauge, through all the usual PIR, beam and contact sensors to some more esoteric devices like an 8x8 thermal camera.

Ian Mercer
Ian Mercer
Cover Image for Why smarthomes are hard

Why smarthomes are hard

Why automated learning is hard for a smart home. The perils of over-fitting, under-fitting and how the general unpredictable nature of life makes it hard to build a system that learns your behavior.

Ian Mercer
Ian Mercer
Cover Image for Event blocks

Event blocks

Home automation systems need to respond to events in the real world. Sometimes it's an analog value, sometimes it's binary, rarely is it clean and not susceptible to problems. Let's discuss some of the ways to convert these inputs into actions.

Ian Mercer
Ian Mercer
Cover Image for Logistic function - convert values to probabilities

Logistic function - convert values to probabilities

Another super useful function for handling sensor data and converting to probabilities is the logistic function 1/(1+e^-x). Using this you can easily map values onto a 0.0-1.0 probability range.

Ian Mercer
Ian Mercer
Cover Image for ATAN curve for probabilities

ATAN curve for probabilities

In a home automation system we often want to convert a measurement into a probability. The ATAN curve is one of my favorite curves for this as it's easy to map overything onto a 0.0-1.0 range.

Ian Mercer
Ian Mercer
Cover Image for Home Construction Advice

Home Construction Advice

Several years ago we did a major remodel. I did all of the finish electrical myself and supervised all of the rough-in electrical. I also put in all of the electrical system and water in our barn. I have opinions ...

Ian Mercer
Ian Mercer
Cover Image for T-Mobile home internet

T-Mobile home internet

I'm testing a T-Mobile Home Internet device as a backup to XFinity and a way to offload half our monthly traffic to avoid the XFinity 1.2TB cap

Ian Mercer
Ian Mercer
Cover Image for Probabilistic Home Automation

Probabilistic Home Automation

A probabilistic approach to home automation models the probability that each room is occupied and how many people are in that room.

Ian Mercer
Ian Mercer
Cover Image for Multiple hypothesis tracking

Multiple hypothesis tracking

A statistical approach to understanding which rooms are occupied in a smart house

Ian Mercer
Ian Mercer
Cover Image for A state machine for lighting control

A state machine for lighting control

An if-this-then-that style rules machine is insufficient for lighting control. This state machine accomplishes 90% of the correct behavior for a light that is controlled automatically and manually in a home automation system.

Ian Mercer
Ian Mercer
Cover Image for Home Automation States

Home Automation States

Understanding the many different 'states' a house can have is critical to creating great home automation

Ian Mercer
Ian Mercer
Cover Image for Graphing gigabytes of home automation data with tableau

Graphing gigabytes of home automation data with tableau

Some interesting charts from the gigabytes of data my home automation system produces

Ian Mercer
Ian Mercer
Cover Image for iBeacons for Home Automation

iBeacons for Home Automation

My investigations into using iBeacons for home automation

Ian Mercer
Ian Mercer
Cover Image for iBeacon meetup in Seattle - January 2015

iBeacon meetup in Seattle - January 2015

My notes on the iBeacon meetup in Seattle held in January 2015

Ian Mercer
Ian Mercer
Cover Image for N-Gram Analysis of Sensor Events in Home Automation

N-Gram Analysis of Sensor Events in Home Automation

Using n-gram analysis to spot patterns in sensor activations

Ian Mercer
Ian Mercer
Cover Image for Xamarin Forms Application For Home Automation

Xamarin Forms Application For Home Automation

Building a Xamarin Forms application to control my home automation system

Ian Mercer
Ian Mercer
Cover Image for The Internet of Hubs (and things)

The Internet of Hubs (and things)

Maybe it should be called the Internet of Hubs instead

Ian Mercer
Ian Mercer
Cover Image for Showing home status with just a single RGB LED

Showing home status with just a single RGB LED

Multicolored LEDs can convey a lot of information in a small space

Ian Mercer
Ian Mercer
Cover Image for A wireless sensor network using Moteino boards

A wireless sensor network using Moteino boards

The diminutive Arduino boards include a powerful transmitter/receiver

Ian Mercer
Ian Mercer

JSON Patch - a C# implementation

Ian Mercer
Ian Mercer
Cover Image for The home as a user interface

The home as a user interface

Ian Mercer
Ian Mercer

A RESTful API for sensor data

POSTing data to a home automation system from Arduino devices

Ian Mercer
Ian Mercer
Cover Image for The Internet of Boilers

The Internet of Boilers

An experiment to measure every aspect of an HVAC / boiler system

Ian Mercer
Ian Mercer

VariableWithHistory - making persistence invisible, making history visible

A novel approach to adding history to variables in a programming language

Ian Mercer
Ian Mercer
Cover Image for A Quantified House - My Talk to the Seattle Quantified Self Meetup

A Quantified House - My Talk to the Seattle Quantified Self Meetup

My talk to the Seattle Quantified Self meetup

Ian Mercer
Ian Mercer

Integrating an Android phone into my home automation system

Some new features for my home automation using an Android phone

Ian Mercer
Ian Mercer

Before there was the web there was BeebTel

Just thought I should mention that I built a web-like system before the web existed

Ian Mercer
Ian Mercer

My first programme [sic]

At the risk of looking seriously old, here's something found on a paper tape

Ian Mercer
Ian Mercer
Cover Image for The Internet of Dogs

The Internet of Dogs

Connecting our dog into the home automation

Ian Mercer
Ian Mercer
Cover Image for GreenGoose Review

GreenGoose Review

A review of the now defunct GreenGoose sensor system

Ian Mercer
Ian Mercer
Cover Image for Home power meters revisited

Home power meters revisited

Ian Mercer
Ian Mercer
Cover Image for Home Automation Calendar Integration

Home Automation Calendar Integration

Ian Mercer
Ian Mercer

Web site crawler and link checker (free)

Ian Mercer
Ian Mercer

Smart home energy savings - update for 2010

Ian Mercer
Ian Mercer
Cover Image for A smart power strip

A smart power strip

Ian Mercer
Ian Mercer
Cover Image for What does a Smart House do at Halloween?

What does a Smart House do at Halloween?

My favorite home automation features for Halloween

Ian Mercer
Ian Mercer
Cover Image for Home Automation Top Features

Home Automation Top Features

Ian Mercer
Ian Mercer
Cover Image for Weather Forecasting for Home Automation

Weather Forecasting for Home Automation

Ian Mercer
Ian Mercer
Cover Image for How can I tell if my house is smart?

How can I tell if my house is smart?

Ian Mercer
Ian Mercer

Home Automation Block Diagram

Ian Mercer
Ian Mercer

Elliott 803 - An Early Computer

Ian Mercer
Ian Mercer

World's Smartest House Demonstration

Ian Mercer
Ian Mercer

Looking forward to the new year and our new datacenter

Historical note about moving my servers into a datacenter

Ian Mercer
Ian Mercer

Future proof your home with a new conduit system?

Running conduit can be expensive but maybe you don't need one to every room

Ian Mercer
Ian Mercer

Second Drobo Update

At this point things were looking up for my Drobo

Ian Mercer
Ian Mercer

It's all about disk speed

Why disk speed is the most critical aspect for most modern PCs and servers

Ian Mercer
Ian Mercer

Comcast woes and a new monitoring utility

Monitoring a cable modem using its HTML management interface

Ian Mercer
Ian Mercer

Core duo desktop machine runs cool

Ian Mercer
Ian Mercer
Cover Image for New Home Automation Server

New Home Automation Server

Ian Mercer
Ian Mercer
Cover Image for World's Smartest House

World's Smartest House

Over 15 years of experimentation with home automation

Ian Mercer
Ian Mercer
Cover Image for World's Smartest House Videos

World's Smartest House Videos

A collection of videos about my smart home efforts

Ian Mercer
Ian Mercer