The 433 frequency is close enough to the 440 frequency, and that receiver looks like it is not very selective, and so if some nearby radio amateurs were running the maximum power that they can legally use, the link would probably be disrupted. So interference could be an issue. That was my motivation for my suggestion.
And the posted link demands that I purchase a subscription, which I did not. And there was no option to continue that I could see.

 

The 433 frequency is close enough to the 440 frequency, and that receiver looks like it is not very selective, and so if some nearby radio amateurs were running the maximum power that they can legally use, the link would probably be disrupted. So interference could be an issue. That was my motivation for my suggestion.
And the posted link demands that I purchase a subscription, which I did not.

I am surprised that you hit a paywall, NYT allows a certain number of free reads before that. Did it have an option to continue?

 

@LAOADAM These small form factor NRF24L01+ breakout boards would be a good choice for you. They will do what you want, on a band that permits it, and they are pretty cheap but much more sophisticated than the 433MHz boards.

​

This does mean something of a learning curve. You talk to them using SPI, and they have quite a few potential configuration options but it gives you a chance to learn SPI if you don't know it, and these radios are generally useful and come in compatible, larger, longer range implementations with PAs (Power Amplifiers) for extended transmit and LNAs (Low Noise Amplifiers) for extended receive.

There is a tutorial on the Arduino website to get you started. I think you'd find them very good for a variety of things.

One more thing: these adapters will your life easier. There is also a version that includes a 3.3V LDO if you are using a 5V MCU.

​

 

I am surprised that you hit a paywall, NYT allows a certain number of free reads before that. Did it have an option to continue?

Happened to me, too. And in my case, I’d already hit my free limit.

 

If this is the tale about Hams finding the source of the interference, and it being an arcing neaon sign in the midde of the bock, I read it elsewhere quite a while back. That was evidently a very broadband signal.

 

If this is the tale about Hams finding the source of the interference, and it being an arcing neaon sign in the midde of the bock, I read it elsewhere quite a while back. That was evidently a very broadband signal.

No, it is about an “experimenter” who was using 315MHz remote control modules in a way that had them transmitting constantly and with too much power.

 

hi Adam,
What data are you planning to send by these modules.?
E

Thank you for asking.
actually, this topic is kind of beyond what I was looking for cause of my wrong words 'decoded ?'.

what I really want to do is let a piece of 433MHz or 315 whatever send out command like： commandA, commandB etc. that's way simple than we discussed and it can be done easy by a Arduino now.

 

I have used two sets of those
modules, connected directly to on-chip USARTS on A Tiny2313 and a USB to serial adapter for two way communications without any special encoding.

I am not in the United States.

thanks.
I guess what I used is a kind of toy level, it is far from any provisions of restricted now? the distance between 433mhz Transmitter and Receiver is less than one meter without an antenna in my testing; can be about 5-6 meters with an antenna?

 

I don't like that the regulatory issues can cause friction, but I have several reasons i am specially interested in letting people know about the actual rules. You may or may not care about those reasons like I do, but here's something of a cautionary tale you should be aware of. When you are reading it, please keep in mind that although the incident involved the 315MHz band, the 433MHz band is also widely used in consumer items, alarm systems, door control systems and countless other applications.

[This appears in a non-technical newspaper, so it will be light on the technical details, but it's been covered elsewhere.]
A Mystery Frequency Disrupted Car Fobs in an Ohio City, and Now Residents Know Why​

Thanks.
which band is for amateur and safety?

 

@LAOADAM These small form factor NRF24L01+ breakout boards would be a good choice for you. They will do what you want, on a band that permits it, and they are pretty cheap but much more sophisticated than the 433MHz boards.

View attachment 261883
​

This does mean something of a learning curve. You talk to them using SPI, and they have quite a few potential configuration options but it gives you a chance to learn SPI if you don't know it, and these radios are generally useful and come in compatible, larger, longer range implementations with PAs (Power Amplifiers) for extended transmit and LNAs (Low Noise Amplifiers) for extended receive.

There is a tutorial on the Arduino website to get you started. I think you'd find them very good for a variety of things.

One more thing: these adapters will your life easier. There is also a version that includes a 3.3V LDO if you are using a 5V MCU.

View attachment 261884​

Thanks.
I've ordered them.

 

thanks.
I guess what I used is a kind of toy level, it is far from any provisions of restricted now? the distance between 433mhz Transmitter and Receiver is less than one meter without an antenna in my testing; can be about 5-6 meters with an antenna?

Small wire antenna through a transmit/receive switch at each location. I tried a distance of 20 meters with a couple of interposing brick walls and it worked fine, and didn't try a different distance. I guess my point is that you don't need sophisticated encoding techniques like Manchester encoding if the receiver is pretty good.

 

Thanks.
I'll ordered them.

The official RF24 library is designed to be easy for beginners. "Easy" is relative, of course. There are examples. and many basic tutorials on YouTube. The NRF24L01 is very popular for RC use, so there are probably some good remote control videos, too.

 

hi Adam,
If you decide on the 433MHz or NRF, I have both types on the bench, so I could check/help with the Arduino Coding.
E

 

A suggestion for an alternative approach that requires no RF design or equipment, and no licensing and can easily work over a few meters distance would be an infra-red data link. Use a receiver similar to the TV remote control unit, and a simpe current control scheme for any number of IR LEDs. It woud be cheaper and simpler and avoid many problems. The commercial versions are already available, marketed as Li-Fi.

 

Bill,
IF you read the TS's Threads, the TS has already purchased, investigated the IR method and has chosen an RF solution as a possible a better alternative,

E

 

Bill,
IF you read the TS's Threads, the TS has already purchased, investigated the IR method and has chosen an RF solution as a possible a better alternative,

E

OK, evidently I lost track of that. Certainly there are quite a few IR systems that are far from suitable.

 

Bill,
IF you read the TS's Threads, the TS has already purchased, investigated the IR method and has chosen an RF solution as a possible a better alternative,

E

I re-read this thread twice and I see no mention about IR linkage at all .I f iit was on a different thread then I do not recall it. And if it was for a different application then that is even farther away.
But no mention was made on this thread.

 

the TS's Threads,

 

hi Adam,
If you decide on the 433MHz or NRF, I have both types on the bench, so I could check/help with the Arduino Coding.
E

Thank you ericgibbs.
I really appreciate it.

 

A suggestion for an alternative approach that requires no RF design or equipment, and no licensing and can easily work over a few meters distance would be an infra-red data link. Use a receiver similar to the TV remote control unit, and a simpe current control scheme for any number of IR LEDs. It woud be cheaper and simpler and avoid many problems. The commercial versions are already available, marketed as Li-Fi.

Thank you MisterBill2.
I tested some IR, some things made it not as good as RC, such as: Anti-interference ability； kind of slow; and easily be separated by objects.