I'm working on a project which will need a one way wireless switch. Basically, the arduino will have a receiver and it will "listen" for a specific signal, and when it receives that signal it will trigger an action. All I need is a simple triggering mechanism, not two-way communication. Is there a simple way to achieve this with a single arduino (ie without a second arduino just for sending a signal)? The distance I need is roughly 30' without a line of sight (through a ceiling and two walls).
From my research the best way to do this would be via an RF receiver and transmitter, but I can't find anything which would allow me to send a signal from a simple RF transmitter without an arduino on the transmitting end. Is there a way to set up a simple circuit without an arduino with an RF transmitter to send a preset signal that the receiving arduino will listen for?
Simple garage door opener system comprising remote control transmitter fob and receiver unit that gives a logical (0 or 1) output signal. Receivers generally operate from DC. See the link for an example
If you take the casing off the transmitter fob you'll see how the press buttons are fitted to the circuit board. You can solder on a pair of wires to give you an input facility from whatever it is you require to trigger the transmitter
Just make sure you get one specified for long range to ensure you get the signal to penetrate the walls
Thanks for the info! It looks like garage door openers are pretty pricey and also quite bulky though. Maybe it would be easier to just create an arduino compatible circuit on the transmitter side, something like this: http://arduino.cc/en/Main/Standalone
That way I will not be wasting an entire arduino to just sit in a remote forever. Would that work? I have never built a standalone arduino circuit before - are there any limitations to such a circuit, or if a program works on a regular arduino board it will work on the circuit 100% of the time?
arduinster:
Thanks for the info! It looks like garage door openers are pretty pricey and also quite bulky though. Maybe it would be easier to just create an arduino compatible circuit on the transmitter side, something like this: http://arduino.cc/en/Main/Standalone
That way I will not be wasting an entire arduino to just sit in a remote forever. Would that work? I have never built a standalone arduino circuit before - are there any limitations to such a circuit, or if a program works on a regular arduino board it will work on the circuit 100% of the time?
Thanks!
Yes, that would work. Depending on the complexity of what you need on the transmitting side, you may even be able to get away with an ATTiny85 or ATTint84.
The last link sent by iggykoopa seems like it would be the easiest to implement, but I've never done anything like this either so it would be good if someone with experience can confirm that this could work. If it's as simple as attaching one of the output pins from the receiver to the arduino and reading if the signal is high or low that would be great.
arduinster:
I'm working on a project which will need a one way wireless switch. Basically, the arduino will have a receiver and it will "listen" for a specific signal, and when it receives that signal it will trigger an action. All I need is a simple triggering mechanism, not two-way communication.
One way to do this is to use some other radio based trigger/receiver. For example, you can get radio based camera shutter release for about $20 on ebay, and hack up both the transmitter and receiver cables. For most cameras, a shutter release just has 3 wires (ground, focus, and fire), that when connected, tell the camera to focus or fire. While I tend to use Olympus myself, I believe some Canon and Pentax cameras use standard 2.5mm phono cables, which might things a little easier.
If you had line of sight, you could use infra-red, but that's not an option.
In terms of a second Arduino, that's an option as well. You could get something like an adafruit DC Boarduino or USB Boarduino fairly cheap. I believe Xbee provides wireless options.
Note that in my case, I just need several transmitters sending a fixed message to one receiver, which would interpret what transmitter is trying to comunicate with him.
I have use the following transmitter/receiver combo for many interesting projects and they work very well.
If you use the encoder and decoder chips you eliminate a lot of problems with interference from stray signals.
They also have an indoor range of about 200 ft and work through walls.
Hope this helps.