How to interface Raspberry PI with x10 to read switch statuses and toggle them on/off? (new system, pre-wired house)

Question

I've been reading on the x10 documentation on the web, so please correct me if I'm wrong on these items:

X10 type parts available

(A) data receiver/transmitter to be plugged in a wall

(B) computer interface that uses data receiver/transmitter to send commands and receive statuses

(C) lamp module - allows you to turn a lamp on and off (lowest power usage)

(D) on/off appliance modules - meant to control small appliances like coffee makers and toasters.

(E) screw-in lamp modules - meant to controll lights including ceiling lights

(F) wall socket module

(G) 3-way switches - allows a physical button, as well as x10 automation

Existing wiring types:

(1) normal on/off switch with a lightbulb

(2) pairs of 2-3 toggle buttons, connected to a relay that turns on/off a light switch (light switches at the bottom and at the end of the stairs). The relay receives pulses and turns lights on/off

(3) wall sockets

What i can do

• some solder expierence

• bash, c, c++, php, mysql, some python and perl and other things

• install and compile software for linux

Hardware Questions

H1. To control the "toggle buttons + relay" (existing wiring type 2) what do i need? can i just connect something to the relay?

H2. I want to also be able to read the status for each socket/lamp module to store it into a db and later on use that data to create stats - if i can get the 'on at X time, off at Y time, and the power usage in W/hour i can calculate a rough estimate of the cost to run that. What controller do i need for this? And do i have to poll each X seconds/minutes the x10 devices or is there a service for linux that can trigger a command when a device is turned on/off?

H3. If i want to keep the current on/off switches, is there an x10 device that i can connect to them inside the wall? Or should i switch to push-buttons, relays and x10 and use everything like that?

H4. Can the range of the x10 modules be extended? When the signal is too weak?

H5. When the devices are on another powerline, is there a bridge? Or is my only option buying multiple controllers and connecte them to as many PI's as needed?

My main concerns are the pc-power line interface and what to do if the x10 interface does not reach the x10 modules, what options do i have. Having multiple controllers and pi's isn't the best solution I'd like but i would implement that.

** Resources **

• About Debian x10 page http://www.aboutdebian.com/x10.htm

p.s.

any links that answer these questions are welcome, i will add the text here for future reference.

Answer 1

Some answers for you:

H1. I guess you could just connect everything to this relay, as long as it doesn't dissipate more power then the relay contacts can handle or have a very odd/extreme cosine-phi factor. The toggle button will act like a manual ON/OFF switch, so you can control the connected device using this switch and x10.

H2. I found out that the modules that I found in a quick search online, do not report the status back without asking for it, meaning what you will have to poll these types to know if they are still on. About the power dissipation: I suppose you tell your database what type of lamp you use (the wattage?), because I haven't seen devices (yet) that actually measure the current and report that back. Meaning that you need to provide the power of the lamp for your calculations, and if the lamp breaks the system will not know this and assume/continue to calculate full power while it is actually broken and thus off. (I would not be surprised if there are devices that DO current measuring/sensing, there are a lot of companies that make x10 stuff, but the costs of these devices will be higher)

H3. You cannot keep your original wall switches, if you want full control from x10. You can if you settle for x10 control with a manual override OFF switch. Meaning that you can turn stuff ON or OFF using x10 as long as the manual switch is in the ON position (when connected in series). Manual switch OFF will be dominant. If you connect the two switches in parallel you have the opposite, you can use x10 to turn devices ON or OFF as long as the manual switch is in the OFF position. Manual switch ON will be dominant. Both solutions in my opinion work awkward, so replacing the manual switch might be the most optimal solution.

H4. Yes, there are signal boosters, repeaters and devices that do this in combination with your H5 question.

H5. There are 2 or 3 phase repeaters/bridges on the market. They 'virtually' connect the 3 phases (!! ONLY for the x10 signal of course !!)

Unless you have a Very big installation, you do not need repeaters, if you have 2 or 3 phase connection you only need to bridge those using a bridge like you suggested in H5. In the case you DO have a Very big installation, you'll also need a couple of repeaters, but get those when needed.

Hope this helps.