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Topic: NRF24L01 transceiver and 315/433MHz RF links (Read 4634 times) previous topic - next topic

rnelias

Can someone make any comment about the differences in applications between these 2 RF modules.

Here are the modules I'm talking about

NRF24L01 transceiver:


315/433MHz RF link:


I know they work in different frequencies and both are pretty cheap but, since I'm not familiar with electronics (I'm more a programmer), I can't decide which one would be better for an application requiring 5-8 transmitters sending a small fixed message to just 1 receiver placed, at most, 100 meters avoiding noises and interferences.

thanks for any help.

PeterH

The NRF24L01 comes with an optional amplifier and external aerial. I've only used the low power ones like the one shown here. In my experience they're OK for transmission over a few yards as long as there's nothing in the way but I wouldn't expect to get tens of yards.
I only provide help via the forum - please do not contact me for private consultancy.

innersky

While I did not yet used it myself, I'd avoid the 315/433MHz RF as they are less reliable. (at least, that is what I read about using these frequencies)
I plan to use the NRF24L01 myself extensively, as soon as I can find some spare time :-)

PS you can find a real nice implementation for the NRF24L01 here : http://maniacbug.wordpress.com/2012/03/30/rf24network/
or here some hello world examples: http://maniacbug.github.com/RF24Network/examples.html

--
hth,
Bart
Check out my Arduino projects website: http://www.arduinopassion.com

rnelias


The NRF24L01 comes with an optional amplifier and external aerial. I've only used the low power ones like the one shown here. In my experience they're OK for transmission over a few yards as long as there's nothing in the way but I wouldn't expect to get tens of yards.


hummm... a few yards would not be enough in my project... :(

I'm looking for a RF link to apply in a RC lap time system. The cars would have transmitters that would send their ID's as soon as they cross a trigger line (I'd use hall sensor and magnets for it). Thus, an Arduino wired to a receiver would read the ID's and collect the time info.

I'm also concerned if the NRF24L01 would be a interference source for the RX/TX used by RC cars since they generally use 2.4GHz links.

here is the link for the RC lap time project I'm thinking about: http://arduino.cc/forum/index.php/topic,111510.0.html

winner10920

I've used the nrf24l01 about 50 feet away through a house and it worked 90% of the time,
but programming wise they are reallly nice and easy to implement, better I think than the other modules

aayotee

There are a few things to consider:

The first is more software/hardware - the NRF24L01 uses a proper protocol, is controllable via a library and probably has some handshaking and error checking/correction.  I'm not entirely sure what the 315/433MHz ones are, they may or may not include these things, or it may be that they are literally a transmitter and modulator, and you have to provide the data that's to be sent.  In terms of implementation it might make it more difficult/challenging, and if you have multiple devices you might not be able to distinguish between the two.

The second is more the nature of the EM waves they emit.  Generally speaking, lower frequency means lower power, better penetration, and longer range.  So the 314MHz/433MHz transmitters may perform better in situations where there isn't a direct line of sight etc.  However, an efficient antenna at 2.4GHz is easier to make on a PCB, so performance may be equal.


One last thing is that as you're looking at *cheap* solutions (i.e. not sparkfun branded), the actual implementations may vary.  Someone may have a decent NRF24L01 and get great performance, and someone might have a badly made one and find it's not satisfactory.  But I guess that's the nice thing about cheap components, if they work then great, if not then you aren't losing much for them to go in the parts drawer and for you to buy something better.  For the project you have described however I would imagine that both will perform well.

innersky


There are a few things to consider:

The first is more software/hardware - the NRF24L01 uses a proper protocol, is controllable via a library and probably has some handshaking and error checking/correction.  I'm not entirely sure what the 315/433MHz ones are, they may or may not include these things, or it may be that they are literally a transmitter and modulator, and you have to provide the data that's to be sent.  In terms of implementation it might make it more difficult/challenging, and if you have multiple devices you might not be able to distinguish between the two.

The second is more the nature of the EM waves they emit.  Generally speaking, lower frequency means lower power, better penetration, and longer range.  So the 314MHz/433MHz transmitters may perform better in situations where there isn't a direct line of sight etc.  However, an efficient antenna at 2.4GHz is easier to make on a PCB, so performance may be equal.


One last thing is that as you're looking at *cheap* solutions (i.e. not sparkfun branded), the actual implementations may vary.  Someone may have a decent NRF24L01 and get great performance, and someone might have a badly made one and find it's not satisfactory.  But I guess that's the nice thing about cheap components, if they work then great, if not then you aren't losing much for them to go in the parts drawer and for you to buy something better.  For the project you have described however I would imagine that both will perform well.


I've noticed that dealextreme recently started selling a very cheap NRF24L01 version. (other than displayed) I wonder if they're any good...

--
Bart
Check out my Arduino projects website: http://www.arduinopassion.com

rnelias


I've noticed that dealextreme recently started selling a very cheap NRF24L01 version. (other than displayed) I wonder if they're any good...
--
Bart


This is the cheapest that I've found: http://www.ebay.com/itm/10PCS-Arduino-NRF24L01-Wireless-Transceiver-Module-/251062580786?pt=LH_DefaultDomain_0&hash=item3a747ef632#ht_2671wt_873

not sure about quality...

rnelias


There are a few things to consider:

The first is more software/hardware - the NRF24L01 uses a proper protocol, is controllable via a library and probably has some handshaking and error checking/correction.  I'm not entirely sure what the 315/433MHz ones are, they may or may not include these things, or it may be that they are literally a transmitter and modulator, and you have to provide the data that's to be sent.  In terms of implementation it might make it more difficult/challenging, and if you have multiple devices you might not be able to distinguish between the two.

The second is more the nature of the EM waves they emit.  Generally speaking, lower frequency means lower power, better penetration, and longer range.  So the 314MHz/433MHz transmitters may perform better in situations where there isn't a direct line of sight etc.  However, an efficient antenna at 2.4GHz is easier to make on a PCB, so performance may be equal.


One last thing is that as you're looking at *cheap* solutions (i.e. not sparkfun branded), the actual implementations may vary.  Someone may have a decent NRF24L01 and get great performance, and someone might have a badly made one and find it's not satisfactory.  But I guess that's the nice thing about cheap components, if they work then great, if not then you aren't losing much for them to go in the parts drawer and for you to buy something better.  For the project you have described however I would imagine that both will perform well.


Good points indeed! I've chosen these two RF links since they are the cheapest, easiest and simplest wireless links that I've found googling about arduino and rf links. There's a bunch of example sketches using 315/433MHz RF links and, some of the examples that I've found for the NRF24L01 show some difficulties with the library, but there are also nice and consolidated projects using this link as posted by innersky.

My main concern regarding my specific project would be:

-- Reach: at least 50 meters (168 ft) without any obstacles. Not sure if the cheapest version of the NRF24L01 (those without antennas) would cover it.

-- Interference: RC cars use 2.4GHz between receiver and transmitter. Not sure if the NRF24L01 would interfere with the TX/RX controls of the cars.

-- Reliable: no packet losses when transmitting a very short message once per minute. Well, both seems to attend this demand.

-- Cheap. Both are cheap (less than 7 usd a pair TX/RX)


spirilis

#9
Jun 28, 2012, 03:24 pm Last Edit: Jun 28, 2012, 03:26 pm by spirilis Reason: 1
Having toyed with the cheap PCB trace antenna version of the nRF24L01+ plenty, I doubt it'd pull off that range.  The RP-SMA jacked version (for a wifi antenna) should IMO especially with no obstacles in the way.  Maybe even with a jacked unit on the transmitter side and a PCB trace version on the other, xmit power set to max on both ends.

Keep in mind the PCB trace antenna version I have is even cheaper than the one you listed, it doesn't have any zig-zag in the trace just a "7" shaped trace.  The zig-zag trace might work better, I don't know.  SparkFun also sells one with a "chip antenna" (those things intrigue me, how well do they actually work?) which might be nice.  The RP-SMA jacked one uses more power due to an RF amplifier onboard between the nRF chip and the jack.

GR0B


I have been using the NRF24L01+ and for me they perform much better then the 315/433 RFlink units I tested.

I found the nRF24l01+ much more easier to get working reliable and at greater range then the 315/433 RFlink units.

For the nRF24 units I tried Manicbugs lib but ended up settling on the MIRF lib as was easier to get working with my boards. 
As for range the really cheap nRF24 units give me a range of about 30meters (indoors) but if you get a one of the more expensive version with LNA and PA for you base station you can get much longer range.



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