Cheap X10 Thermostat Solution

[zion2]

Hi all,

I'm trying to make a cheap X10 enabled thermostat system.

I've got a Digimax 210 X10 RF Thermostat and the corresponding RF receiver. The problem with this is that its not actually programmable! There is only a set-point capability.

So, I was thinking, instead of rigging up the receiver straight to the boiler (like you normally would), I am going to connect it to something like a Powerflash module and transmit a signal to my PC which is running Activehome/HAL2000 or something similar when the thermostat switches the receiver on. Then I can use a separate applicance module or X10 module to control the boiler and setup some rules and schedule on the PC.

The Digimax receiver switches 240v, does anyone know how I can connect this to a Powerflash module? I presume I need some kind of load and obviously don't want to waste any power....

Any ideas/comments?

Thanks,

Zion

[toscal]

You will also need something that can read the security X10 RF codes. Either an SC9000 or similar alarm panel or one of the rfxcom devices.

[zion]

Originally Posted by toscal

You will also need something that can read the security X10 RF codes. Either an SC9000 or similar alarm panel or one of the rfxcom devices.

That's the point - I don't think I do:

1) User sets desired temp on thermostat
2) Thermostat tranmits signal to recevier which turns output on/off
3) Powerflash module interprets receiver output and sends X10 command to ActiveHome
4) ActiveHome responds according to rules and transmits signal to appliance module

So if this concept works, I don't need a SC9000 or RFXCOM. The only thing I can't figure out is 3).

Thanks,

Z.

[toscal]

Oops.
You just set the code on the power flash and every time it gets a contact closure it will transmit the on code for the one you set. I think it also transmits the off code when there is no contact.
So if the power flash is set to A1 then when there is a contact closure from the Digimax RF unit the powerflash will send an A1 On . If you are going to do it that way you could actually bypass activehome etc. As you could just set the appliance module to A1.
What rules do you want to use if you go via activehome.

[TimH]

From: http://www.letsautomate.com/10258.cfm?

Triggered by Contact Closure OR Low Voltage 6-18V (AC, DC or Audio)

So the simplest solution may be to wire a regular socket in series with the thermostat contact so when the contact is closed the socket is powered. Then plug a 12V wall-wart type power supply into the socket and connect the power supply's output to the PowerFlash contacts.

Depending on where you live you might want to hardwire a frost-stat in parallel with the room stat so in the event of cold temperatures you will always have some heat in the system. X10 does not guarantee the transmission of messages and if you (i.e. the boiler) miss the one-shot "ON" signal from the room stat you won't get any heat until the user "resets" the thermostat.

HTH,

Tim.

[zion]

Originally Posted by toscal

Oops.
You just set the code on the power flash and every time it gets a contact closure it will transmit the on code for the one you set. I think it also transmits the off code when there is no contact.
So if the power flash is set to A1 then when there is a contact closure from the Digimax RF unit the powerflash will send an A1 On . If you are going to do it that way you could actually bypass activehome etc. As you could just set the appliance module to A1.
What rules do you want to use if you go via activehome.

Thanks for your reply. Yes I'm almost there I think. I don't want to bypass Activehome as I want to setup some rules (more below) and if I was doing that I would just connect the DigiMax receiver straight into the boiler.

Right, so the DigiMax receiver switches 24v to 240v so I could plug that into the mains and then rig it up with a 240v-12v transformer on the output (as TimH rightly suggested), and connect that to the Powerflash module in mode 3. That way whenever the Digmax thermostat trips one way or the other, an X10 signal will be transmitted on the powerline.

Does Activehome actually support if/then rules by the way? I.e IF thermostat tripped on AND weekday AND before 10pm THEN switch appliance ON??

The final piece in the jigsaw is an appropriate driver module for my boiler. To trigger my boiler PCB I need to provide a closed contact which is capable of handling a 240v load (unknown current). So I need a 240v equivalent of the 'Universal Module' - do these exist?

On the missing signal issue - my existing X10 equipment is of the newer variety that supports two-way commands - i.e. it can be polled to test its status - I intend to do the same with the boiler system so I can check if the boiler was turned on or not. Then the only weak point in the chain is the Digimax system.

Thanks again,

Z.

PS I should add that I know I could just use a normal programmable thermostat but eventually I am intending to purchase HAL2000 and an RFXCOM for a more advanced system - but in the meantime I really need a thermostat!

[toscal]

From memory so I may not be 100% correct, activehome only supports if then statements via the PC, these macros cannot be downloaded to the cm11/12. The downloadable ones are called fast macros.
Yes there is a relay board but it has 8 relays on it rather than just 1. You may want to take a look at WGL Designs http://wgldesigns.com/relay8.html

Personally I would go for a CM15 pro and the Activehome Pro software, rather than the normal Activehome as the pro can have if then else logic based macros which you can download to the CM15.

[zion]

Originally Posted by toscal

From memory so I may not be 100% correct, activehome only supports if then statements via the PC, these macros cannot be downloaded to the cm11/12. The downloadable ones are called fast macros.
Yes there is a relay board but it has 8 relays on it rather than just 1. You may want to take a look at WGL Designs http://wgldesigns.com/relay8.html

Personally I would go for a CM15 pro and the Activehome Pro software, rather than the normal Activehome as the pro can have if then else logic based macros which you can download to the CM15.

Hi,

Thats OK - I'm happy to run the if then statements on the PC itself - no problem with that - especially as I already have a cm11.

Thanks for the link to the board I'll check it out!

Z.

[zion]

Originally Posted by toscal

Yes there is a relay board but it has 8 relays on it rather than just 1. You may want to take a look at WGL Designs http://wgldesigns.com/relay8.html

PS Could I not just use a universal module with another 12v transformer and a single relay capable of switching mains loads on the output side?

In fact, couldn't I just use an AD10 directly?

Z.