Hi,
I mean can I use a 433MHz Transmitter to send coded data by Arduino? or maybe it can only send a fixed code as manufacture set?
Thanks
Adam

433MHz_T:

433MHz_R:

 

Hello,

of course you can, but you have to handle signal modulation and encrypt send data on your own.

Best Regards

 

in the US, the radio service in the 433MHz band in pretty narrowly defined. In particular, the only data you are permitted to send is along with a remote control signal. It is not the right band for data transmissions.

§ 15.231 Periodic operation in the band 40.66-40.70 MHz and above 70 MHz.
(a) The provisions of this section are restricted to periodic operation within the band 40.66-40.70 MHz and above 70 MHz. Except as shown in paragraph (e) of this section, the intentional radiator is restricted to the transmission of a control signal such as those used with alarm systems, door openers, remote switches, etc. Continuous transmissions, voice, video and the radio control of toys are not permitted. Data is permitted to be sent with a control signal. The following conditions shall be met to comply with the provisions for this periodic operation:…

The proper bands for data transmission are the 915MHz (LoRa) and 2.4Ghz (NRF24L01/NRF24L01+). For LoRa, you are probably going to want an ESP32-based board with the LoRa module in place. For the NRF24L01 you buy a module and there are libraries for Arduino compatibles.

 

Hello,

of course you can, but you have to handle signal modulation and encrypt send data on your own.

Best Regards

Thanks

 

in the US, the radio service in the 433MHz band in pretty narrowly defined. In particular, the only data you are permitted to send is along with a remote control signal. It is not the right band for data transmissions.


The proper bands for data transmission are the 915MHz (LoRa) and 2.4Ghz (NRF24L01/NRF24L01+). For LoRa, you are probably going to want an ESP32-based board with the LoRa module in place. For the NRF24L01 you buy a module and there are libraries for Arduino compatibles.

Thank you Yaakov.

 

I suggest using the 315 MHz band instead. With that little transmitter for na short distance and a short time it wi not get any attention or cause interference. Aso,what sort of data do you intend to send?? Radio signals are not at all private, you know.

 

I suggest using the 315 MHz band instead. With that little transmitter for na short distance and a short time it wi not get any attention or cause interference. Aso,what sort of data do you intend to send?? Radio signals are not at all private, you know.

Operation on unauthorized bands is both illegal and unnecessary. The options I provided are legal and better anyway.

 

315 is a key-fob band.

 

315 is a key-fob band.

Which is authorized for remote control not data. Why not use allocations that permit data transmission with hardware designed to do it?

 

in the US, the radio service in the 433MHz band in pretty narrowly defined. In particular, the only data you are permitted to send is along with a remote control signal. It is not the right band for data transmissions.


The proper bands for data transmission are the 915MHz (LoRa) and 2.4Ghz (NRF24L01/NRF24L01+). For LoRa, you are probably going to want an ESP32-based board with the LoRa module in place. For the NRF24L01 you buy a module and there are libraries for Arduino compatibles.

Hello,

I only respond to technical possibility, I didn't know law limitations in USA.

Best Regards

 

Hello,

I only respond to technical possibility, I didn't know law limitations in USA.

Best Regards

Oh, I understood that. I hope you didn't take my post as chastisement, it wasn't meant that way. The regulatory aspect is often overlooked and people seem to assume if they can buy something that transmits it means it's legal to use.

 

Getting back to the original question. Those modules do not, by themselves, send data. They only turn the carrier on and off. Turning this into data transmission is up to the user.

Bob

 

Certainly the speed at which the transmission can be switched on and off, (modulation) will matter for the data transmission speed. It is very possible that the data rate desired is faster than what the transmit modue can handle.

 

I think they claim 10K baud, but I found that 1K was more like it.

Bob

 

I suggest using the 315 MHz band instead. With that little transmitter for na short distance and a short time it wi not get any attention or cause interference. Aso,what sort of data do you intend to send?? Radio signals are not at all private, you know.

Thanks.
Just control a toy car.

 

Getting back to the original question. Those modules do not, by themselves, send data. They only turn the carrier on and off. Turning this into data transmission is up to the user.

Bob

Thank you.
I see.

 

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

 

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.

 

Those modules do not, by themselves, send data. They only the carrier on and off.

(Please do not interpret this as a political statement)

Just like the fact that guns do not, by themselves, kill. They only send a lethal projectile when the user presses a ‘button’.

Both end results are illegal (in the US).

 

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​