Bridging the Gap Between Nest and Line Voltage Thermostats


I recently decided to switch my old thermostat to a Nest and figured that it should be easy considering my current thermostat just controlled a simple electric wall heater. Unfortunately, it was only after taking my old thermostat off the wall that I realized that it was in fact a line voltage thermostat (Honeywell’s T410AA), which means that it uses high voltage (240 V) and acts as an in-line switch between the electric wall heater and the power supply. The problem with this is that systems like the Nest run off of low voltage (24 V) and can’t be used to switch a high voltage system.

To fix the issue I started researching. Surely I wasn’t the only person who wanted to switch their old school line voltage thermostat with a Nest! Unfortunately, a bunch of the solutions were on Nest’s old community site which had since been taken down. However, I was able to find out about a relay/transformer that according to the reviews should be able to bridge the gap between line voltage (240 V) and the typical low voltage setup used for modern thermostats like the Nest (24 V). The schematic for it shows the method for hooking it up to known thermostat wires.


The Aube Relay RC840T-240 does exactly that. It takes 3 wires carrying the line voltage (connected to Black, Blue, and Red) and then connects them out via 3 wires (R, C, W) carrying low voltage. This works to connect the line voltage wall heater with controls from the Nest system.


After connecting everything up, I tested the Nest to see if it worked and low and behold! It worked like expected. The only thing left after wiring and testing the setup is to mount it properly. However, the relay/transformer does not fit inside the original electrical box so I will need to devise a workaround to get it to all fit within the wall up to code.

Read the Continuation here:

Amazon Echo Has Promise for the Future

I got an invite to buy an Amazon Echo a while ago, but didn’t want to purchase one because it didn’t seem particularly useful. It’s only advantage to me was the SDK for speech that might be of use in the future.

After seeing the initial intro video and how scripted the commands had to be, I couldn’t justify the purchase.

If I wanted to get answers to questions I have, I would just pull out my phone and type it out rather than dealing with Speech-To-Text inadequacies when asking a long question. If I wanted to add something to a list, I would write it down on my notes or use my phone for the same reason.

I could play music using a voice command, but to be limited to my Amazon Music Library, Prime Music, or Pandora? No thanks, my audio receiver will do a better job with the audio quality in my home anyways.

On top of that, waiting for a delivery date a couple months later? No thanks.

The Turning Point

That was it, I forgot all about the product until recently. That was when I saw a couple Youtube videos showcasing hacks of the system to configure voice commands for other things! Now this is where it really gains some useful functionality.

Imagine using the mic array and speaker in the Echo to pick up your voice commands and give you audio feedback to commands you create yourself. As a developer, this would have unlimited possibilities in the home! My heart skipped a beat once I saw someone using it for these purposes despite the lack of an official SDK and I immediately started imagining the improvements I could make to my current projects in the home automation space and quickly came up with a couple scenarios that I “need” it for.

There are the typical scenarios like turning on or off appliances and lights in your home, but then there are bigger home automation scenarios where you would communicate with the Echo like you would a personal assistant.

Imagine waking up in the morning and talking to Echo and having it relay specific things you care about like the weather, news, calendar updates, family updates, etc. while also having it turn on the shower so it’s running at your preferred temperature by the time you jump in. Have it make your coffee so that when you get out of the shower, it’s ready. No need to preset things the day before, or stick to a generic schedule. It’s all voice activated.

Now imagine coming home from a day at work and asking it to turn on a specific “mood” for your home, like “summer breeze” that would open your blinds, open your windows, put on some light music, turn on just the right amount of lighting, etc. Have your home work for you!

It looks like Amazon is starting to see the value of this use case with the Echo too, because they recently announced an update that would allow their default voice commands to work with WeMo switches and Hue lights, but those are just basic scenarios.

After all my excitement about being able to create custom commands, I decided to purchase one (despite the couple months I’ll have to wait to finally receive it).

Still a Couple Faults

  • Works well for one room or an open-concept home, but you’ll need separate ones for each room if you want it to work everywhere. (Or maybe an extension of it in other rooms?)
  • From the demos online where people use it, it looks like their speech recognition system isn’t up to par with most of the other speech recognition system, yet.

Autonomous Driving Coming Soon

Recently Tesla announced that in the summer of 2015, Tesla cars would receive a software update to enable an autopilot feature (on highways) as well as a valet-like feature that could park the car for you and be summoned via a smartphone (on private property). This is going to change the world as we know it; the next step, fully autonomous cars.

“Tesla had been testing its autopilot on a route from San Francisco to Seattle, with company drivers letting the car navigate the West Coast largely unassisted.” – Elon Musk

As of right now everyone has a couple clear concerns. The main fears being “what if something were to go wrong with the autopilot feature” and “what if someone were to get into an accident while in the vehicle”. While this is a valid concern and certain regulations need to be in place to decide who would be responsible, there will obviously be rigorous testing and scrutiny on the new Tesla systems. Let’s not let our fear of the new and slightly unknown cloud our judgement.

These concerns will likely be similar to those expressed by the major news outlets in 2013 when a couple Tesla vehicles caught fire (all due to accidents). The statistics behind it tell the real story. According to the National Fire Protection Association

One vehicle fire per every 20 million miles driven by a conventional car vs. one vehicle fire per every 100 million miles in a Tesla.

If there is an option that we already have experience with, we are more likely to choose that option simply because of its familiarity. Sure there could be a robot uprising and our cars could drive us all off a cliff.. (woops I just added another scenario), but that would be unlikely.

“For consumers concerned about fire risk, there should be absolutely zero doubt that it is safer to power a car with a battery than a large tank of highly flammable liquid.” – Elon Musk

The main unsafe factor in normal driving is the person behind the wheel. In 2010, there were an estimated 5.4 million crashes! Imagine if you took the human element out of the equation. Autonomous cars would not speed, get distracted by phones, cut each other off, drive recklessly, or park like a** holes and leave you with two inches to squeeze your whole body out of your door. They would have faster reaction times, be better able to assess the situation, and even go a step further and provide services to people who could not drive themselves! Some of those scenarios are not ready currently due to the need to be tested vigorously under different situations. But the truth of the matter is that if done correctly, the cars would be safer than putting a human behind the wheel.

Back to current reality

How Tesla’s update could benefit us:

  • Autopilot during the commute home in traffic jams! Let the system auto-brake, speed up, stay within the lines and get you most of the way home safely without you ever having to lift a finger or foot.
  • Autopilot on road trips to relieve some of the stress when driving long distances
  • Reduce the number of car crashes and traffic jams as a result (tell the horrible drivers to get one)
  • Have a valet in your own home! You can get out of your car and let it park itself in the garage.
  • Make more people interested in an electric vehicle!
  • Paving the way for a new generation of automobiles that have the ability to drive for us.

Issues with the update:

  • What if regulations don’t allow the feature to be used in certain areas? The disparity could cause problems.
  • What if the software doesn’t live up to the expectation and actually causes accidents? (low chance of happening but is a possibility)
  • What if people who are driving their cars hit a Tesla and claim that it was the Tesla or Tesla driver’s fault? (easily fixed with cameras and sensor information from the Tesla)
  • Who is responsible if the accident is because of the Tesla?