The Blog of Ian Mercer.

World's Smartest House

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Welcome to my blog. In here you'll find articles about my multi-decade-long pursuit of the "world's smartest house" and other passions. My smart house technology controls heating, lighting, sprinklers, music and more. It talks over the speakers, it plays music by tags in any collection of rooms, and you can even chat to it on messenger using natural language.

Home Automation

Articles about #homeautomation describe a system that includes over 200 sensors within a house and nearby barn that together create an environment where you don't need to touch a light switch during the course of a typical day, where the heating operates in an optimum manner, and where music plays across multiple rooms controlled by a natural language interface.

You'll find blog posts on my favorite features, a discussion on representing the home as a graph and much more.

You'll find posts about #sensors including strain-gauges, PIR, optical beam, microwave-doppler and Bluetooth including the pros and cons of each technology and my experiences with them.

If you want to dive into the technical details around how the house became smart you'll find articles on many of the techniques I've tried including things like #multiple-hypothesis-tracking. So take a look at #homeautomation.

Natural language meets home automation

Natural Language Engine

You'll find a few articles here about the history behind my natural language engine for .NET, but head over to nlp.abodit.com for the full picture. My NLP engine is unique in the way it integrates into an existing .NET desktop or server application. Responding to sentences is as simple as writing a method with the permutations of tokens you want to recognize. It offers full intellisense support for meanings (Synsets) with dictionary-like definitions. It handles permutations and optional phrases, it handles grammar production rules and it includes a large set of existing tokens that can recognize numbers, formulas, units of measure and the widest set of temporal expressions possible. And by temporal expressions, I don't just mean picking a datetime from the input, I mean expressions that can represent infinite ranges (every sunday in May) and complex expressions like last sunday after 5pm. My natural language engine is also a probailistic parser able to return a sequence of possible parses in descending order of likelihood. It understands some of the ambiguity in the english language like the fact that 'and' sometimes means 'or'.

Travel and Photography

And last, but not least, I'm also documenting some of my favorite travels and photos, so check out the Photography and soon Travel topics below.

Technical Details

This blog was created using next.js, a ReactJS static web-site generator. I converted an existing sample blog to Typescript and added a recommendation engine to display relevant "More reading..." articles after each article that you read. This is all driven using YAML front matter on markdown posts, the entire navigation structure is derived from a 'priority' field, a 'date' field and a 'tags' field on each post.

Related Stories

Cover Image for Time Series Data Compression

Time Series Data Compression

This new technique to compress the time series data collected by my home automation system seems to be working really well.

Ian Mercer
Ian Mercer
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 Natural Language Processing

Natural Language Processing

I could not find a Natural Language Processing engine when I needed one for my home automation system so I developed my own. After 10 years of on and off development I now have a unique NLP engine for .NET that is easy to configure but incredibly powerful for precise command and control applications. It doesn't use a tokenizer so it doesn't care if you run words together.

Ian Mercer
Ian Mercer
Cover Image for Bluetooth Tracking Project

Bluetooth Tracking Project

My year long Bluetooth project that won the $20,000 HCI and Microsoft competition during lockdown has continued to grow and now reliably tracks how many people are in the house and outside and can locate any device down to room level.

Ian Mercer
Ian Mercer
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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 Collinearity test for sensor data compression

Collinearity test for sensor data compression

One way to reduce the volume of sensor data is to remove redundant points. In a system with timestamped data recorded on an irregular interval we can achieve this by removing co-linear points.

Ian Mercer
Ian Mercer
Cover Image for 3d Printed ESP32 Brick

3d Printed ESP32 Brick

ESP32 provides a great platform for sensors around the house but by the time you've added a USB power brick, cable and enclosure it's quite messy. I wanted a device that I could just plug in with no exposed wires and no mounting needed so I designed one in OpenSCAD.

Ian Mercer
Ian Mercer
Cover Image for Bluetooth Sensing for Home Automation

Bluetooth Sensing for Home Automation

Bluetooth sensing for home automation is a great proxy for people counting as it can detect and locate each cellphone in the house. iBeacons attached to tools, cars and pets can provide a 'find my anything' feature too.

Ian Mercer
Ian Mercer
Cover Image for Microwave Doppler Sensors (RCWL-0516)

Microwave Doppler Sensors (RCWL-0516)

Microwave doppler sensors can be found in some alarm sensors but there are also available very cheaply as a separate component. They offer exceptional range but suffer from false triggers requiring a probailistic approach to people sensing.

Ian Mercer
Ian Mercer
Cover Image for Optical-beam sensors

Optical-beam sensors

Optical-beam sensors are reliable and can cover a long-distance such as across a garage or aisle-way. When they include multiple-beams they have good false-trigger rejection.

Ian Mercer
Ian Mercer
Cover Image for PIR Sensors for Home Automation

PIR Sensors for Home Automation

PIR sensors are cheap and easy to use but they suffer from slow response times and low repeat rates.

Ian Mercer
Ian Mercer
Cover Image for Strain-gauges

Strain-gauges

Strain-gauges are my top-rated sensor for home automation because they are invisible, reliable and can be tuned to detect people and ignore pets.

Ian Mercer
Ian Mercer
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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
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Bluetooth

One of my inventions recently won a $20k global competition for applications that could help in a pandemic. It uses Bluetooth to count people.

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 Home Automation Systems as a Graph

Home Automation Systems as a Graph

Using nodes and links to represent a home and all the devices in it

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
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
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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

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

World's Smartest House Demonstration

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
Cover Image for New Home Automation Server

New Home Automation Server

Ian Mercer
Ian Mercer
Cover Image for HX711 Strain Gauge Pulsor Sensors

HX711 Strain Gauge Pulsor Sensors

Using Pulsor sensors with an HX711 for homeautomation.

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
Cover Image for Pressure Sensors for Home Automation

Pressure Sensors for Home Automation

Pressure sensors can detect HVAC system operation and could potentially detect clogged filters.

Ian Mercer
Ian Mercer