Archive for category Design
I just got the confirmation email that I’ve been accepted to have a booth at this year’s Maker Faire. The booth is called A Sense of Things, as it was last year, and is numbered 7443. I hope to visit with all my sensor friends on Saturday and Sunday, May 19th, 20th.
I’ll be showing our latest development on a low cost wireless sensor network designed for the “everyman” or “everywoman” who wants to track things in and around their homes. Please stop by for a visit.
To sign up for the maker Faire: http://makerfaire.com/be-a-maker.csp
$250? Why does cool have to cost so much?
I have been building my own home wireless sensor network for the last 2 years. Temperature, light, hall effect, gas detection, FSRs, the Tweet-a-watt, etc. using XBee modules and a wifi gateway that uses an open source OS (OpenWRT) and Python scripts to send data to web services (like Pachube.com, ThingSpeak, Open.Sen.se). I’ve been studying home energy automation for a couple of years now and I’m beginning to understand the various aspects of what it takes to put together components to collect and communicate meaningful, actionable information.
The Nest Learning Thermostat has some cool features. It learns… and that’s fantastic. As I understand it, you can set the thermostat up or down at different times and it will remember what you set and build a schedule that repeats your preferences. That’s very cool. It has a motion detector to sense the presence of people in the house and turns the system down/off. That’s cool, too. But there are some serious issues that I see over and over in this field.
First off this device costs too much. It should be priced at somewhere below $50 for the thermostat. That would put it at a price point to get it into the homes of many more people. The more consumers use it, the more we can reduce our dependence, as a nation, on foreign sources of energy. That’s a national, heck, a global goal, right?
Next, I don’t see any way to help consumers understand meaningful and detailed results of the savings they create by using the thermostat. They might see an overall drop in their gas or electric bill, but how much can be attributed to the thermostat as opposed to the incandescent bulbs they replaced with CFLs, or by the shading of a porch, or by being more diligent in turning off the entertainment system (including the STB) and vampire loads.
Also, the designers have created a thermostat in a very traditional form. IOW, they’re not “thinking different”. The learning aspect is interesting, but I’d rather just go to my android app, or the web site and just start with a default profile for my region, house size, etc, and adjust to taste. Otherwise, I’ll not look at it again unless there is an exception to the rules, like going on a long weekend vacation.
Similarly, the designers are stuck with the concept that we need a thermostat on the wall and that we would ever want to get up off the couch and go look at it. Why spend the effort in a device that shouldn’t even require a UI. IOW, the phone app or web page should be the preferred UI.
A “think different” approach might have a temperature sensor and a motion detector in each room and these very cheap components can inform the HVAC controls how to adjust for optimum comfort vs cost. The display and controls don’t need to be on a wall in the hallway… That’s as old as the the round Honeywell thermostats people were referencing in the comments on the Wired Magazine article.
I also believe that the display devices that you get with most home automation system, perhaps in the style of elaborate refrigerator magnets with displays, are destined, too soon, for garage sales and Goodwill stores. Let’s extend the devices that we already have for control surfaces, like tablets, smart phones, game consoles. For those who don’t have smart phones in their homes, how about something like a cheap android phone form (w/o the phone functions), music players, remote controls, wifi tether devices; any devices that can support apps.
I believe profit is deserved by all who work but how much is enough? If you look at Chris Anderson’s approach describing how to make a profit on your products (), you would sell at 2.3 times the cost of parts; and that’s a good profit margin. If I did my math right, it looks like the BOM costs about $108.
I suppose they might be adding in some of the costs of running a free web service that stores all the data so clients can see the ongoing history of their thermostat settings correlated to the temperature of their house and the local weather.
Lastly, my impression is that the design isn’t finished. Design doesn’t stop until you’ve optimized the functionality, the design, and the cost. In this era of programmable microcontrollers, arduino shields, MEMS sensors, surface mount components, standard protocols, inexpensive cloud based web services, the Internet of Things… we need to delight consumers by making the products attractive, pervasive, and affiordable… for everybody.
Tendril has a post on their blog that talks about an emerging style of energy monitoring connectivity that they are calling a Hybrid-HAN (home area network). It envisions a dual network, one that utilizes a the Utility’s smart meter and a second provided b y the consumer; a wifi router, for example. They figure this is a good thing because it will unburden the smart meter from the growing list of sensors and controls that will become more popular as consumers learn to understand the benefits of monitoring their home environment.
The consumer side of the system uses something called the ZigBee Smart Energy Profile. Not sure about the Smart Energy Profile but Zigbee is a well known low power wireless protocol that I’ve been experimenting with for a low power, inexpensive monitoring system. Each Zigbee (aka xBee) module can transmit or receive signals that cover most residential buildings and costs about $20.
Interestingly the image shows the data from the consumers gateway (basically a specialized router) being fed back to the utility company but I’m not sure that’s the way it will play out.
In the future, data locality will not be so crucial. There are always concerns about this or that silo of data that stands alone and unaccessible from external sites. But as we grow to understand the benefits of shared data, any system will be able to aggregate date from any other system (with proper authentication of course).
Once the smart meters have replaced your old analog power meters the next step is access to the appliances in your house allowing your power provider to control when you use those appliances.
Interesting to think about….
Here’s an interesting post on Home Energy:
Announced at CES 2010, this is a wifi enabled device that sits between a house appliance and the wall socket. It has a small linux based OS and web site so you can access each device via a web interface.
It can monitor the energy use as well as control the device so it does a lot. Sadly, it it said to cost about $80 each.
TOO Expensive. Seems like a low tech Kill-a-Watt ($20) and a spreadsheet would still be more efficient.
Remember the old mechanical watches that used to wind up by wrist motion? They utilized an offset weight that spun around inside the watch and slowly but surely kept the watch wound up. Well here’s a cell hone that does the same thing. I’m sure it’s expensive.
What other items could we power this way?