Ars asks: What home automation project should we tackle?

Was surprised to see pic of an IMP insides during my Google Reader review.

Arstechnica is asking it’s readers what home automation project should we tackle using an Electric IMP.

Oh the possibilities…Thanks for sharing.

Ok how about a poor man’s NEST room thermostat.
With a good temp sensor in like Sensirion STS21 i2c temperature sensor it’s got 0.2% accuracy and its $3.93.

Motive: Heating & Cooling are the major part of your energy costs & I need one…

Ok how about a poor man's NEST room thermostat.

I ended up reading about the electric imp more because of that ars technica article, with exactly that goal in mind.

I found this on the wiki: jane – seems like just what I’d need. But, I’m a software developer, not a “hardware guy” – I haven’t touched a soldering iron in 10 years. So, am I best off just waiting for things to mature more, so that I can just buy some pre-made hardware and program it do do my bidding? I also couldn’t seem to find anywhere to buy the development boards completely assembled, so I guess you’re supposed to just buy all the parts on the bill of materials, get someone to print the circuit board from the data files on the wiki, and solder it all together yourself?

pioto: where are you located?
Pre assembled - April Sparkfun
I haven’t used a soldering ion for a long-time either but has been great fun re-learning. Jane’s a reference design and suited to USA HVAC system. I’m in the UK we don’t run our HVAC like that so was thinking of a standalone stat with OLED display. You may want to check AdaFruit they I believe will have some impee boards coming soon.

I’m located in the US, and from what I remember, I have 3 24 VAC lines for my HVAC (Heat, Air Conditioning, Fan), with a 4th “hot” wire to connect to each of those to trigger things. Unlike newer wiring over here, I don’t have a 5th “common” wire that I could use to allow the system to draw power directly from my HVAC transformer, so I’d need to instead power this off of batteries. From various bits that I’ve read about the electric imp, though, this should be a lot more possible than with, say, an Arduino?

I saw AdaFruit was supposed to have stuff soon, but apparently not yet. I’ll keep an eye out there, though. Hopefully, if pricing is about what it looks like it should be, I’d be basically spending something < $30 for the “impee”, hopefully including the relays, thermal sensor, etc, and $30 for the imp itself? That compares pretty favorably to my previous research into this project, where I think I was planning on using a pair of XBees or something… with my “home server” basically reading the temperature, and sending relay toggles, using the XBee by itself.

Hugo, has indicated somewhere on the forum that for raw life support you can run on CR123 battery + SD slot and id chip. I think this config is dependant on next card-os release but it might try it out this week. If you run server.sleepfor() battery drain is low. Getting data back to your “homer server” is easy if your ruining a web server on it, I am do all my data login I used to use EnOcean wireless sensors similar to XBee. But the e.imp platform is a joy to use the guys have just made it so easy.

Well, yeah, I saw I can basically have the imp code do a HTTP POST to the web service of my choice. But, an equally important thing for my ideas is… can I have external services send things to it?

Basically, a key part of my idea for imitating “NEST” is to simulate the “away” mode, only, I intend to decide that we are “away” if neither of our cell phones are on the WiFi network (so, something that I’d have code on my home server figure out periodically, and then notify the IMP about).

Cool so “away mode” is based on Neither mobile device being present on you home wifi network. No idea how you do this, can you poll your router to see if your phone is connected e.g. using mac add?

This post might help

Yeah, I have my own DHCP server being used (dnsmasq), so I can either check when the DHCP leases are added/expired for the devices, or, just ping them.

I am also a software developer and have no background in hardware of things. If I did however, I really wanted to NESTify my multi-zone HVAC system. Like a typical US home, I have 2 thermostat controllers. They are incapable of automatically switching between heat and cool. In the Spring and Autumn when temps outside hover around desired temp, I have to run around the house manually switching hot/cool at least twice each day. So, if i knew how to wire this imp board up to interface with that switch in my existing Honeywell/White-Rogers thermostat, the rest is very easy. The software part only needs access to accuweather to get the temps outside for its logic.
I also have a sprinkling system in the house without a rain sensor. Even with the sensor, what good is it if the rain will occur 5 minutes AFTER you wasted $3 in water? An Imp would hookup into my existing Hunter controller box (which has a breaker board hookup for rain sensor already), fetch weather forecast and convert that to “it’s raining now, don’t run regularly schedule program this time”.
Anyone care to kickstart these two? I’ll gladly buy your products ahead of production :slight_smile: Or, help me do the hardware interfacing and I can do the software.