Hi everyone. I'm trying to control RF power outlets using an Arduino. I've connected a 433 MHz receiver module and loaded up the "ReceiveDemo" sketch from the rcswitch library to detect signals. I also soldered a 7 inch wire to the receiver module to as act an antenna.
While I'm able to capture the signals from the remote control, the remote needs to be within half an inch from the antenna wire. Anthing farther results in no signals being detected. On the other hand, the receiver is able to capture signals from my wireless door sensor from over 4 feet away.
What puzzles me even more is that the remote and the wireless outlets have decent range by themselves. The remote is able to trigger the power outlets consistently from over 7 feet away.
Question: Why is the detection range so short between the remote control and the RF receiver module? How can I improve the detection range? Thank you!
I've just started out with the Arduino and I'm having the same problem as well trying to read the HomeEasy protocol. Reception only works a few millimeters away. Transmission works a lot better though, but haven't tested the limits .. 6-7 meters at least (without any antenna! And using a generic Ebay transmitter no less!).
Tried both the generic Ebay receiver as well as a Velleman RX433N (which has a pin for antenna). In fact, antenna or not doesn't in fact seem to make much of a difference as the range is still only millimeters from the antenna.
Also, while checking the voltage I noticed that I get a drop when the network shield is connected between the protoshield and the uno. Connected to a 5V USB battery, I get 4.95 with just the protoshield and 4.75 with the ethernet shield. Even worse when I run it from my computer usb. Is this something to worry about? Velleman claims an operating voltage of 5V +/- 0.05V. Even so, the transmitter doesn't seem to care (3V-12V obviously). Perhaps I can find a 12V powerbrick and see if it makes a difference.
Edit: 12V psu still only gives 4.95V on the protoshield. Forget what I said about voltage, these receivers are probably functional down to 4.5V.
Your protoshield might have a voltage regulator, so that it steps down to 5 V everything it has on the input. Try powering your transmitter directly from 12 V PSU (I suggest 9 V PSU, however - just not to burn anything) that is - connect VCC of transmitter to +12 V of PSU, GND of transmitter to GND of PSU and also to GND of Arduino (or protoshield that is properly connected to Arduino board), DATA of transmitter to the TX pin you use.
Hi Guys,
I have used a 433MHz Rx to intercept my Bios Weather station signals to decode the same with an Arduino. I have also written a program to mimic the signals coming the Bios system using a 433MHz Tx. The reception of the Rx was not a problem, in fact when I was trying to test my transmitter, even putting the test Tx (minus antenna!!!) and RX in an aluminium pot with the lid on did not stop signals reaching my weather station Rx (>7m away) and injecting wrong readings. In the end I got smart and took the RF out and just fed the Tx Arduino directly into the Rx Arduino, problem solved.
I would be suspicious the remote system you are tapping into may not be exactly 433MHz? I ran mine tx and Rx all on 5Volts and had no problems with signal strength even with prototyping board set up. See photo. In the Remote's specs you quote, it says the remote operates on 315MHz?
Its important that the supply voltage for those el cheapo 433 Mhz receivers is as close as possible to 5V.
The frequency stability of the onboard oscillator which sets frequency isnt all that great and drifts with variations
of supply voltage, which causes the receiver to appear to be insensitive .
Measure the voltage with a multimeter right on the receivers supply pins , especially if the receiver is being powered
from a power source which also has to power other things.
Thank you for your Audacity samples,
however a decent digital signal should look like below.
What I saw from you signal was half random stuff and the bit that was not really convincing.
I think you need to swap to 315Mhz receiver and not try to use 433Mhz
I am completly new to this forum so please excuse me if i am repeating a topic already but from the bit of reading i have already done, ye are talking about way more advance stuff then i am, so this one should be a piece of cake.
I am trying to exploit a 433 mhz receiver and sender board to act as a proximity alarm.
Basically if i have a whole pile of these boards (about 4) i would like to profile the transmissions so that if
Person 1 carrying board 1 comes within range of receiver, the receiver will output to led 1 and maybe also sound a piezo.
Person 2 carrying board 1 comes within range of base receiver, the receiver will output to led 2 and maybe also sound a piezo.
and so on and so fourth.
I am guessing that this is bread and butter stuff for you guys on here but i am electronically minded but cannot program, a little bit of visual basic is the height of it.
My contribution to this of thing resides at 433MHz_Tx_Rx. It might give you some ideas as to what you could do.
Generally speaking you will need to have your 433Tx pulsing out a broadcast at regular intervals and the 433Rx listening all the time. The 433MHz band, for your style of application, does not permit continuous Tx, and any way it would quickly drain the batteries if they are AA's or AAA's.
Once you have the Tx and Rx talking to each other you can work out a system to give each Tx and ID in its code and then have the Rx code be able to discriminate between the Tx's. Given you only need to change 2 bits to identify each of 4 Tx's, you can prune the length of the headers and packet to the bare minimum and save on your Tx energy usage.
If you decide to use the code I suggested, I can give you further help if you have difficulties, however there are many other ways to do this sort of thing (eg the Arduino Single Wire library, from memory) and feel free to choose what ever works for you.
Thanks very much for that rob, sorry about my delay , i lost this forum , i understood most of that but when u started talking programming i got lost , i will try your code when i get my transmitter, when i get them talking i might come back to you to see if you can tweek it for me thanks
Here in South Africa, hams are co-primary users on 433MHz. I assume the other "side" of the co-primary arrangement is the garage door openers and so on.
Ham regs state that we have to give our call sign once per transmission; that's usually interpreted to mean once per over.
If I as a ham was to use Rob's linked code (or any other, of course) for 433MHz I wonder if I would need to send my call as one of the data elements. What's it like worldwide?
A non-ham would obviously not have a call to send, but since I am one, I maybe I need to? That would be crazy overhead where my 6-character call might be bigger than the data!
What's it like worldwide?
(Of course the absurd conclusion could be that hams' garage door openers might need modification to send the call sign just because we are hams )
I think there are probably two main differences between a Ham on 433MHz and a Garage Door opener. The first would be the power of a Garage Door opener would be a flea power compared to a Ham transmitter and only have a very local range. Secondly the duration and modulation of the Grarage Door openers (and Weather Stations etc) is short bursts of simple information, say 30-50 milliseconds every 45 seconds, or in the case of a Garage Door opener, maybe once or twice a day. So I suspect that you will not have to worry about your Ham responsibilities with regard to the little flea powered transmitters we buy on the Internet.
Another factor that I can't be sure of but I suspect is that the 433MHz Tx and Rx a Ham would use would have fairly tight bandwidth control and power requirements. Because our little Tx and Rx setups operate with a On-Off keying (like Morse code I guess), the flea power Rx's and Tx's are probably fairly rough and ready. I think if they were really sophisticated, like our Wi-Fi setups, then we would have bands inside that 433MHz range that we would need to stick to. It is really just a general purpose band really, with few legal requirements if used as intended.
Just my 2c worth,
Cheers, Rob
PS A local Ham on 433MHz would be very bad news though for my weather station setup , he would win and I would lose!
)
, he would win and I would lose!