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FEZ Controlled AC outlets


#1

I needed to be able to control an AC outlet with a FEZ board. I mounted a GHI Gadgeteer relay module in the bottom of a deep 4" electrical box on 1/4" standoffs. Since I needed a longer cable to run from the outlet back to my FEZ board I soldered an eight wired cable to an extender module and plugged the extender module into the relay board. All of this fits inside the standard 4" AC outlet box.

The other end is a bit messy at this point as I did not have another extender module so I used a Duinoproto. It was good enough to test that everything works. Well almost everything, the 8 wire cable I used was junk so I’ll have to replace it.

Here is a quick video:

This gave me an idea for a module that I call the Gadgeteer LRE (Long Range Extender). Picture a small module with a DB9 and a Gadgeteer 10-pin header. A DB9 actually has ten connections, the 9 pins and the shield. A decent quality DB9 cable will have 9 wires and the shield so you have all ten connections and can easily move a Gadgetter module several feet away from the processor board.

I’ll get a board laid up by tomorrow and start another thread for it.


#2

Very cool Jeff :slight_smile:
Are you controlling each of the four individual sockets… one per relay?
I’m very interested in the idea of extending the connection between the processor board and the relays. Is it necessary to use a shielded cable?
Please let us know how this works out for you.


#3

Good job! What are you using it for?


#4

I know that there are advantages in creating your own AC control device, but have you considered using Insteon or ZWave? I’ve been using Insteon and ZWave with HomeSeer for about 2 years now, and it seems to be reliable. However, I don’t really like having a PC running all the time, and the HomeSeer U/I and API are a bit of a mess, so I decided to create my own automation controller based on NETMF devices. I’m writing a driver for the Insteon 2413U PLM. I have the basic communication working, but I still have a lot of coding to do!


#5

@ jasdev: yes, each socket is individually controlled. The reason for the shielded DB9 cable was so that you have ten wires (9 pins plus shield drain wire).

This will be used to turn a leaf blower on/off. Yes a leaf blower! It is what we will be using to supply air for the FEZ controlled ping pong ball shooting gallery. Since there were four relays it just seemed to make sense to wire up four outlets then the outlet box can be used for a variety of things.


#6

This is very cool and once you you close the metal enclosure, this is done to the code, safe and fire proof.


#7

Are you sure the building code allows mixing low voltage and high voltage equipment in the same electrical box?


#8

It’s only for a temporary project (not embedded in a wall somewhere), so I don’t think building code affects it. Nor do I think it will be running without the supervision of at least a few EE’s. :wink:


#9

This is not a device that will be installed in a house but it is built in a safe manner. The relays provide isolation between the high voltage and lower control voltage.

As far as electrical codes, in the home this would be no different than a device like a sprinkler timer, etc. It is a device/appliance not part of the power distribution system. Industrially you have a lot of times where you have a lower control voltage controlling a higher voltage, to start/stop a motor,etc. Generally you would not run and AC and DC (high voltage / low voltage) in the same conduit; both for noise isolation and so as to not get confused as to what type of voltage level your working with.


#10

I’d love to use that kind of stuff, but it’s TERRIBLY expensive. $50-$120 for a simple on/off wall switch is just too expensive for me to even consider. Is there a more reasonably priced option?


#11

@ godefroi
They are expensive, but building your own could also be expensive if you use ready-made controllers and relay modules. In my house I use Insteon 6-button keypads, zwave door locks, and a zwave thermostat. I want to add a couple more insteon light switches and maybe an irrigation controller. It would be difficult, and I think expensive, to try to replicate those devices on my own.


#12

I’ve got the irrigation controller nearly licked. I’ve got nearly all the software and more than half of the hardware completed (all of it’s designed, it’s just not all built yet). It’s a 16-zone controller.

For thermostat, I’m planning on going with the $100 wifi thermostat available from Home Depot. Simple JSON API, no subscriptions required. It’s perfect!


#13

That thermostat from Home Depot sounds very interesting, I’ll look into it.

I also started developing an irrigation controller based on a Panda II, but I may switch to an Insteon controller instead.

Just a side note… I like Insteon products, they are attractive, well made, and seem to be reliable.
My experience with ZWave is also positive, but I have had more problems with them, and given a choice now, I would go with Insteon all the way. One of the nice things about Insteon and ZWave products is that they don’t need a central controller to interact with each other. You can setup a group/scene that will work even if the central controller is down.


#14

got any link ?


#15

The thermostat is the 3M-50: http://www.homedepot.com/buy/electrical-home-automation-security-home-automation-climate-control/filtrete-7-day-touchscreen-wifi-enabled-programmable-thermostat-with-backlight-182800.html

Read more about it here: http://moderntoil.com/?p=325 and http://moderntoil.com/?p=350

API documentation: http://central.isaroach.com/wiki/index.php/Main_Page

This is the company that actually makes the units: http://www.radiothermostat.com/control.html