Hi there guys and girls,
I have been researching and reading for basically the last couple months and I am nearing the time when I am ready to bring my project into reality, I just have a few things that I need to double check with those that are far more intelligent than I.
My original plan was to have an electrician install a second switch for every single manual light switch in my house, all to a central place say my garage, where i could create an arduino hub for interfacing with 2 x 16 channel relays. I was then told that my idea would be very costly with the running of power lines around my roof by a professional, I began formulating another plan.
I have a whole bunch of leftover cat 6 cable, the plan now is to run cat 6 into every wall cavity that has a light switch. I have purchased a couple of breakout boards and rj45 socket adapters. The plan is to create little 1, 2,3 and 4 channel relays to install within a junction box, within the same wall cavity as the manual switch, I would then send the current to run and the message to trigger the relays through the cat 6 cable from a main controlling arduino mega controlled again by a raspberry pi (but thats another thing in itself).
Obviously, there is the usual warning of dealing with dc and how it should be handled by someone qualified to do so, I just want to check to see if how I picture it in my mind is right as well as a few questions if anyone has the time to help, I would be much appreciated.
Now I have done testing, using rj45 keystone jacks with jumper wires forced into the metal and I was successful in turning a relay on and off through a rj45 keystone port up into my room to my central ethernet hub where another keystone with jumpers was there to receive a message which toggled a lamp on and off. Now...
- The way i picture it in my head is:
You have a normal switch. One state the light is on (when the connection to hot is made), the other the light is off when it is severed. To set this up, you would unwire the wire leading from the switch to the light, you would then get a 3 wire, connect the middle of one end to the hot leading to the light, the other two outer wires to the two manual switch states, then connect the other end of the three wire to the relay (preferably in a formation that that allows the manual switch to be in an off position, with the relay powered down and the light switch is off. (I know I have just confused everyone with that attempt at an explanation, but I hope it made snense)
Is there an issue with this kind of setup, IE using cat 6 to send perform this kind of task, how about when I have a relay setup for every light switch in the house, could it be too strenuous on the cat 6 cable. the longest cable will be around 15 metres I would estimate.
I feel as if this is the type of scenario where I would definitely need to externally power the relays, even whilst doing this, will the arduino struggle to be able to provide pin high to all of the relays in the system at once, is there anything I can do to help it along and or protect the machine in case of a fail.
Having 1,2,3 and 4 channel relays, I havent doubled checked this, but I am pretty sure that they are all 5v relays. Now this is the important one. From talking to people and researching it...is it true that I can potentionally power multiple or even all of the relays from the one 5v power supply, if it has the amps to handle the load? Would a 5v 2A charger be enough to run around 20 relays at the same time. I was also thinking of attaching a current sensor module to each switch, so that I can calculate light usage and check to see whether a light is turned on. Will this have a large affect on my power supply drain.
Lastly, probably a stupid question 5. Say I have a power supply plugged in running at 5v or 12v or whatever it is, if a relay or a door strike or something connected, but it is not currently being used in the circuit is it:
a. using the same amount of electricity as normal
b. using way less, not noticeable amount of electricity and therefore can be left on at all times
3. Either way, its 5v or 12v and its not very much electricity and I shouldnt notice it compared to my oven?
Sorry for the novel and thank you in advance for any help or guidance.
Michael - Keen to learn
Arduino Mega -> cat 6 -> rj45 socket adapter ->breakout Board ->custom perfboard (within junction box screwed to faceplace within wall) --> relay -->Return to arduino through ground
Ps. When I externally power a module do I need common ground or what? People seem to be pretty vague about that...or atleast confusing and everyone says something different.