I was curious if anyone out there has done anything with the Relay Module, using it in combination with a traditional three-way light switch. My idea is to use a board, network adapter and relay module to control a simple light bulb (turn the light on/off in response to a web request); but I’d also like to keep my traditional light switch in place. I’m also curious to know if anyone out there has come up with a way to power a board by wiring it into their normal electrical supply instead of using something like a outlet-AC-Adapter/USB Adapter.
Thanks Andre! Can you tell me more about connecting the relay and the switch in SPCO mode? I followed your link and did some binging. I found the a three-way switch has three poles; two hot and a traveler. The relay module from SEEED has 4 sets of C, NC and NO poles. Do these things fit together, or do I need some other form of relay? Is it simply a matter of connecting the hot to the relay’s common, the light to the relay’s NO and the traveler to the relay’s NC?
I appreciate the feedback - hoping to avoid electrocution.
The setup shown here is a simple switching capability - when either the relay state or the physical switch is toggled position, the light will change state. The setup in the video is more complex - the relay and physical switch are independent of one another, and there is sensing of the manual switch turning on that is detected. Simple or hard, you get to choose what you want to do The simple option is quite easy to retrofit into an existing wired house, but the hard option is often implemented as a low power signaling network to get the switch state, and an active controller detecting that and controlling the lighting
@ Brett - Thanks for the reply Brett. As I’m a novice in electronics, I don’t have any idea about the things you said about (Low power signalling network & active controller to read switch state). But, at any cost, I want to do that project from the scratch…
I barely know that they are using Raspberry Pi for wireless control and I don’t need any guidance in writing codes. I just want to know how that two way control is possible also how the status of lights on that webpage was updated while using manual switches to turn ON/OFF the lights??
So, could anyone please tell me what are all the components I would need & what are all the things I must learn about to successfully do the things I just asked??
Personally I would use a press, touch or proximity switch wired to an input on the microcontroller. This means that the state of the switch is not needed to determine when the light should be on. If a multi way switch circuit is needed like the original poster then a current sensing unit on the light side of the circuit would be needed to determine whether the light switch is providing voltage to the light. However the situation may be different depending on the design of the light circuit e.g. loop in, single and earth or loop through (see House Wiring for Beginners - DIYWiki for more information). If it was a new installation then running the twin and earth from a single light back to a relay box and low voltage cable from the light switch to the micro controller (like the recommended solution for Control4 home automation) may be preferable. There was a cool product that can be retrofitted to a light switch that works over wifi that I saw recently but I have forgotten it’s name… If I find it again I will post it!
No, no it doesn’t operate like a two way switch. The two way switch scenario is the same as is documented earlier in this thread. You can tell this when he turns the manual switches to OFF and then controls from the web, and the lights still come on, but never shows a situation where the light is controlled to ON by the web or switch, then the alternate is used to turn it off.
To maintain state and display it on the website, the simplest way is to use the switches as digital inputs to your controller, and each one’s state is then able to be reflected to the webpage as well as setting the relay’s state to toggle the light. A trickier (sexier?) way is to use press-buttons with indicator LEDs in them as the switches, and still toggle the relay and LED when pressed. This then means you can never get the physical switch and light “out of sync”.
Push button makes this trivial. Detect a button press, and that simply toggles the binary state that you record in your app in the microcontroller. If the light was off, turn it on. If on, turn it off. If the “press” came via the web interface instead, it still acts on the same binary state element, and still carries out the same action. In this condition there is no such thing as “two way” switching; you’re switching from as many elements as needed but it’s simply on or off. This method is actually even more flexible - for a stairway you normally have a two way switch one at the top one at the bottom, and you can have a press button switch in each place but you can also have another switch for that light next to your bedside so when someone goes sleepwalking you can turn the light on for them. Or put master switches somewhere in the fuseboard.
Go back to the superhouse link I gave you and you’ll see a lot more detail about how Jon set that up - its exactly the scenario you are talking about.
Okay Brett, I haven’t been much into this whole electronics thing. Thanks for your guidance. Let me start the work and report back about the work progress…
HI Vickie, did you manage to find a solution, as I am also facing the same problem to combine high voltage switch with a relay as a 3-way switch.
BR. Emir
