I am attempting to build a home automation network. The network will consist of a base station that is an arduino+ethernet shield+nRF24l01 2.4 GHz radio module. The other devices so far are 3way wall switches that consist of an arduino+motion sensor+3 buttons+SSR Relay+RF module. The main focus of the devices is that they can replace any existing home's outlets and wall switches.
The problem.
For obvious reasons, plugging a wall wort into my light switch is a serious eye sore. Base on the wiring, i dont think there is a way to power the arduino from the 120v supply in the switch (to my knowledge). So as a temporary solution, I threw a 9v battery in it worked fine. Unfortunately, after only about 3 hours, it was dead. So I am back to square one.
How can I keep the arduino running at all times without requiring major wiring and or wall surgery?
9v batteries are low milliamps generally, a dedicated sla they are 6v & 12v.
Also look into power saving modes by Nick Gammon, arduino is power hungry lil monster.
I am looking for the links.
Bigger battery?
Little square 9V batteries are only good for a couple hundred mAH.
Power it from 3 D cells, will last a good long time. AAs are good for ~2500mAH, so Cs or Ds should be a lot longer.
Without a way to power down the ethernet shield or the RF module, you will be drawing power all the time.
And you really need them on all the time to be able to receive a command, yes?
You really need a box that goes between your outlet and your appliance that houses the AC switch for the appliance and your electronics so your electronics can be AC powered as well.
An example of one that is one-way comm's only:
Without a way to power down the ethernet shield or the RF module, you will be drawing power all the time.
And you really need them on all the time to be able to receive a command, yes?
Yes, I will need them listening at all times. The ethernet arduino is powered from the wall, it is only the wall switch that I am stuck on.
Do you not have the normal Hot, Nuetral and Ground wires going to your switches and outlets?
It an old house, built around the 1930's. (electrical is probably 80's) I cant mess up the plaster walls, thats why I am in such a pickle. There is only a black and white wire entering into the switch box, Im not an electrician but my understanding is that for this to power the arduino the circuit would have to be closed, meaning when the arduino shuts off the relay, it will be shutting itself off too.
I think they do, but im sure no arduino runs directly from mains. And i think there is minimal cavity space.
Indeed, I will using the guts from an iPhone cube for now as the power adapter.
It an old house, built around the 1930's. (electrical is probably 80's) I cant mess up the plaster walls, thats why I am in such a pickle. There is only a black and white wire entering into the switch box, Im not an electrician but my understanding is that for this to power the arduino the circuit would have to be closed, meaning when the arduino shuts off the relay, it will be shutting itself off too.
Lime Putty walls
The relays coil can be controlled from the board, but the mains is separate, turning off the relay doesn't or shouldn't turn off the board.
A schematic, Diagram or Picture of your setup will make it easier for us to follow.
JB_AU:
I think they do, but im sure no arduino runs directly from mains. And i think there is minimal cavity space.
I realize that. If there is the requisite wiring, then there are small adapters that will fit inside an outlet or light switch.
It an old house, built around the 1930's. (electrical is probably 80's) I cant mess up the plaster walls, thats why I am in such a pickle. There is only a black and white wire entering into the switch box, Im not an electrician but my understanding is that for this to power the arduino the circuit would have to be closed, meaning when the arduino shuts off the relay, it will be shutting itself off too.
Phrases like "i think" and "my understanding" have no place when dealing with high voltages that can kill you. If you're not completely sure of what you are doing, then don't do it.
Phrases like "i think" and "my understanding" have no place when dealing with high voltages that can kill you. If you're not completely sure of what you are doing, then don't do it.
There is no mention of the user wiring anything to the mains, the user is thinking of using a relay but is unsure, they are using a game cube adaptor/adapter. They are trying to fit more into a smaller space.
But it is a valid point, eventually someone qualified will need to wire the mains to the relay to complete the switch. Electricity kills, complacency kills more.
Everyone... Thanks for your concern. Admittedly, I dont have a great understanding of all things electrical but I am aware of the dangers of high voltage and I would not wire anything that I wasn't confident in. I always flip the breaker before working on anything.
I simply want to connect an adapter to the mains and control the light with a relay. The relay on the main that goes to the light fixture is already done and functioning but I am powering the arduino with a DC adapter that is less than attractive. I am just asking if there is a way to access the main without affecting the light fixture, given I have the wiring for a one way switch.
rclymer:
I simply want to connect an adapter to the mains and control the light with a relay. The relay on the main that goes to the light fixture is already done and functioning but I am powering the arduino with a DC adapter that is less than attractive. I am just asking if there is a way to access the main without affecting the light fixture, given I have the wiring for a one way switch.
In order to do that, you would need to wire the device in parallel with the light (although you're still affecting it, it's not at noticeable) Given that there is no neutral wire available in your light switch box, you cannot wire it in parallel.
