Hey Guys,
We've got 2 sets of projectors, projector lifts and projector screens at the church. And these are all controlled using their own remotes. It's a hustle to press buttons on all 5 remotes(2 x lift, 2 x screen and 1 x projector. same remote works on both projectors). Since the projectors are infrared, we have to point them to the projectors, hence going in public to turn them on(not a good idea). So i planned to make a web-based interface to control all the devices from any device connected to the local network. I've worked out the projector remote as its IR. For IR, I decoded the signals sent from the projector buttons im using(ON, OFF, Source). But how do i do this for SAW resonators? I found nothing online for devices operated by SAW Resonators instead of IR. Please suggest a method to do this without the requirement of Scopes as i don't have it and I'm not in budget to buy this now.
You may have to provide more detail, particulary on the RF remotes (sketch of layout, remote control models, data sheets etc) and any info you have found already.
You could of course use IR for all the devices if there are manual switches available to hack into. Alternatively you could just hack into the RF remotes and do up a circuit to get the arduino to effectively 'close' the button contacts on the remotes. (just an idea)
Well the screen and the lift are not of any brand so i wouldn't be able to get any model numbers or datasheets. but i can try to get images which i doubt will help. One more question. Is RF the same as SAW? Because I saw a video of someone using RF transmitter which looked just like a SAW transmitter.
I will have 2 IR leds pointed to each projector. And a SAW resonator to send signals to the other 4 devices. This will all be controlled using a web interface running on arduino + ethernet shield. Hopefully it works out. If youve got better options, please let me know.
Is there a frequency on the device, like 433MHz or 866Mhz, 915Mhz or 2,4GHz or 5.8GHz?.
If you can't identify the model of the RF remote, it will probablbly be a long shot for you & difficult for anyone else to help.
If you can at least get the frequency (look inside the battery slot, if not visible) you could then just buy a cheap transmiter & receiver on eBay to see if you can get it working yourself.
BTW - given your association with a church...whats the thinking behind the tag line on your posts?
And the tagline means that having a high goal and failing after a try is not a crime. but if your goal or vision is small from the beginning then its a problem. i think its a quote by APJ Abdul Kalam. Former president of India.
Ok. Right now you have IR controlled projectors. You want to control them with RF. You say you want to use a SAW. Why does it matter? You could use any module -- Zigbee, NRF24L01, whatever. The "cheap" 443MHz modules typically use a SAW, but since your projectors speak IR they don't know or care what you use on the RF side.
Just FYI, I think using an Ethernet shield and a web interface is serious overkill. It will be faster and easier to just use a standalone Arduino with a couple of buttons ("set up projectors" / "put projectors away") and the RF transmitter. Done, and anybody can use it the day you're out sick. The Ethernet module will add expense and coding time and requires you to have a complicated PC/laptop/tablet/phone set up which takes take 10-100 times longer to open a browser and navigate around to the button you want to push. But, it's your baby...
Bit of confusion here.
A SAW resonator is a passive device that looks like a high Q frequency determining network.
It behaves in a way similar to a crystal, but can work at much higher frequencies.
A SAW resonator doesnt create RF , you still need extra electronics to do that.
Hey tylernt, thanks for the comments and help. ill have to ask other members on making it all button interface. and i think i was not able to explain the setup properly. 2 sensors will be connected to the arduino. 1. IR led and 2. rf transmitter. IR will control projecter and rf will control lift and screen. hope im doing the right thing.
Hey mauried, can please elaborate on what ill have to do. because according to the video i posted, it just works.
That video shows an Arduino transmitting using a 433 Mhz ASK Transmitter.
The Transmitter has a SAW resonator on it , to determine the frequency, usually 433.92 Mhz
but it also has additional electronics on the same little board to actually generate the RF.
The SAW resonator only sets the frequency.
A SAW resonator by itself does nothing.
Ok, it sounds like a relatively standard 433MHz remote,
They typically send a bitstream of 8, 16 or up to 32 bits with some ID & command bits.
I suggest you buy a couple of rx/tx pairs on eBay. You typically get 2 types one is FSK (frequency shift keying?) and the other is OOK (on off keying aka amplitude modulation AM).
The OOK type is the most common type used in my experience, for these types of remotes. They operate in a similar manner to IR remotes, but send RF instead of IR. Unfortunately most manufacturers dream up their own bit patterns so you may have to play around with it a bit first.
My suggestion is that you purchase 1 x FSK pairs & 1 x OOK pairs off eBay and then get your Arduino out etc... Its a lot easier with an oscilloscope or Logic Analyzer, but harder without. (you could also tap into the signal from inside the remote)
something like... (the ones with the 4 pins coming out)
There are many example projects ( 'Arduino + 433 MHz' via google) to show how to approach decoding these devices (which you need to do before being able to send the commands from your Arduino.
