HOME AUTOMATION: Simultaneous Manual and Automated Control

Developing a home automation project: So far I have developed an android app and a relay controlled circuit along with fan dimmers/ speed controller (triac controlled) and everything works just fine.
On a minor demonstration, my professor asked me develop a logic on how could I control the switches both manually and through my android app in sync.

Currently I am connecting the common of all the relays to 240V AC and the load wires to NO (Normally Open) pin of the relays. The thing is the load wires are also connected to the NO of the switch on the switch board itself too where from it gets 240 V if switched on from the board.
Here lies the problem:
I can switch it on and off from the app when the switch is manually off but when it's on i can't switch it off. Because its getting 240V AC from the switch board.

Is there any way I can make both manual and relay operation work in sync.
That is when I switch it off or on from the board/app it switches off and on irrespective of how and what its previous state was and what the source was(App controlled via bluetooth+UNO/ Manually via switch board).
Thanks!

The "manual" switch must be an input to the Arduino, like the bluetooth app.

You can also wire it up like hallway switches, where two switches can change the state of the light but then the Arduino doesn't know what is off and what is on.

Just asked the same thing in another thread, look up 3 way switch diagrams and it should be clear on how to get function down. App knowing state will require actual monitoring instead of linking to one input as a toggled state.

MorganS:
The "manual" switch must be an input to the Arduino, like the bluetooth app.

You can also wire it up like hallway switches, where two switches can change the state of the light but then the Arduino doesn't know what is off and what is on.

So by stepping it down to 5V and taking a digital input will do that?

INTP:
Just asked the same thing in another thread, look up 3 way switch diagrams and it should be clear on how to get function down. App knowing state will require actual monitoring instead of linking to one input as a toggled state.

I can code the state monitoring and send it to the app, but the thing is i dont want to replace the wall mounted switches.

A relay with both normally open and normally closed terminals is needed and connected to that wall switch. Didn't say you needed to ditch the wall switch, but you do need to connect to it. If you actually bothered to go and look at what I said to, you would know what I mean.

INTP:
A relay with both normally open and normally closed terminals is needed and connected to that wall switch. Didn't say you needed to ditch the wall switch, but you do need to connect to it. If you actually bothered to go and look at what I said to, you would know what I mean.

Can you please share the link to that thread or a schematic for such wiring?

Google banned in your country?

INTP:
Google banned in your country?

I could find it dear but was a bit confused. I can find a SPDT relay connected to a 3 way switch but not a normal switch(single pole) or as two 3way switches connected to each other.
Something like

But how to do it for a normal switch?

Your professor has given you a "thought experiment" and there are several approaches which could realize a working prototype.

Clearly, asking here about the approach is going to restrict your freedom to devise a personal implementation - that is, when one enters into a dialog with a group of others, the brain becomes biased. Only when you enter the group as a peer does the interactions induce the magic of new thought.

For example, in the above discussion different members are telling you how they would do the solution posed to you by your professor. You are getting exposure to their thinking but your thinking is not being elevated; rather, I would suggest it is being limited.

Were you to come into the forum with multiple new proposals on how you would implement the solution, then the intellectual engagement of pro vs con would enrich your viewpoint and refine your thinking. Obviously, becoming a peer within a forum group requires both knowledge and peer respect - something that is difficult to obtain (and keep!) Just be aware that by engaging "us" openly, you may miss the big opportunity to figure it out for yourself.

Ray

You need a SPDT, if by normal you mean SPST, then you need to make sure it really is a SPST you have and not a SPDT with an unconnected throw.

Ray, that's a very good way of saying we won't do his homework for him. :slight_smile:

INTP:
You need a SPDT, if by normal you mean SPST, then you need to make sure it really is a SPST you have and not a SPDT with an unconnected throw.

a simple on off switch, with load wire fastened on the upper screw and the live on the lower. SPST.
How to control those ones I am asking.

Thanky ou so much for the advise Ray, I have done a lot of research on it and then came here. I knew about 3 way switching but the switches that i have are on and off switches. So if only you guys could help.

Need SPDT. Not negotiable. Sorry if you've grown attached to that switch. Life is rough like that.

INTP:
Need SPDT. Not negotiable. Sorry if you've grown attached to that switch. Life is rough like that.

I told you that I cannot replace the switches in the very first reply, for demonstration I have to hook it up at the place of exhibition and sadly the exhibition is not at my place.So I can't replace the switches there.

When you don't know, you don't speak. Or at least be a little less rude.

Cool. Then your project is impossible and you're going to fail the requirement. Maybe read up so you can explain to the teach why you couldn't do it.

INTP:
Cool. Then your project is impossible and you're going to fail the requirement. Maybe read up so you can explain to the teach why you couldn't do it.

Let's just concentrate on the issue and not about me failing or passing.
Are all the normal(on/off) switches in your country let say powering a bulb,SPDT? And if not ,how is home automation working?
All switches off from the board and only phone control?

Every single one. It's all we have. I think the government is involved.