Which is better: RFM69 or NRF24L01+?

[NeverDie]

I haven't measured it myself, so I'm very open to everybody's data. Hopefully more people will post results of their own measurements and a pattern will emerge suggesting what's truth.

[shabba]

Just curious if anyone has tested the power consumption yet? But to be honest only one of my sensors is battery powered so I'm not overly concerned :-)

[fets]

@francois where did you get your antenna for rfm69. DIY ?

[mrmin24]

Hi,

Anyone got the Ethernet gateway going with RFM69? I am struggling and I am not sure, but I think there are a few issues in the V1.5 for RFM69.

@NeverDie, a 78mm piece of wire works well for antenna.
*Edit - Sorry, this is assuming 915MHz. See https://www.easycalculation.com/physics/electromagnetism/antenna-wavelength.php and choose quater wavelength

[NeverDie]

@mrmin24 said:

Hi,

Anyone got the Ethernet gateway going with RFM69? I am struggling and I am not sure, but I think there are a few issues in the V1.5 for RFM69.

@NeverDie, a 78mm piece of wire works well for antenna.

Does it make any difference what the wire diameter is? I'm assuming the thicker the better?

[mrmin24]

@NeverDie Probably, but I don't think you should stress too much. The power is not "that" high.

See http://ham.stackexchange.com/questions/140/good-wire-for-wire-antenna for what seems like valid response.

[NeverDie]

@mrmin24 said:

@NeverDie Probably, but I don't think you should stress too much. The power is not "that" high.

See http://ham.stackexchange.com/questions/140/good-wire-for-wire-antenna for what seems like valid response.

Right, I'm just not t sure how to account for the "skin effect".

[Francois]

@fets yes ons DIY. I am using 433mhz radio and I just wound the wire around screwdriver the thickness of the wire is 5.8mm and it is working for me.

[NeverDie]

@Francois said:

@fets yes ons DIY. I am using 433mhz radio and I just wound the wire around screwdriver the thickness of the wire is 5.8mm and it is working for me.

Is it just bare copper, or does it have some kind of thin insulator on it like magnet wire has?

[Francois]

@NeverDie it is just bare copper wire.

[Dwalt]

Bare or insulated wire will work the same. I use insulated on my 433mhz transmitter/receiver node to prevent the antenna from shorting anything on the board, just in case.

[fets]

@francois nice job

[NeverDie]

@fets said:

@francois nice job

+1

[NeverDie]

Here a theory as to why the RFM69x might be better, at least for some people. Broadly speaking, RFM69x apparently has better range under regular conditions. "Well," you say, "I don't need better range. I live in a matchbox. My existing range is fine." Yes, when you're batteries are providing 3.3v, maybe it is. But what about when they're low and supplying closer to 1.8v, or whatever your cutoff is? How good is your range then?

So, my hope is that RFM69x will be sufficiently awesomer that it will have at least as good a range at, say, 1.8v as an NRF24L01+ does at 3.3v.

To be a good, reliable engineering design, you need to build your nodes/system for the worst case: i.e. their range is still effective even when all their batteries are on the verge of cutting out.

So, you could compensate for NRF24L01's lesser range by deploying repeaters, if necessary. However, you might avoid that cost and higher latency and possible deployment/maintenance hassle if you funnel those dollars into nodes that have better radios in the first place.

Anyhow, just thinking out loud here, of another angle on how to decide which is better for you.

[NeverDie]

Looking into it, it's beginning to look as though the RFM69HW can't be scaled back on Tx power by much, if any. That's because, allegedly, it's PA has to be turned on if it is to work at all. So, this may explain why some people are opting for the RFM69W instead.

[NeverDie]

@Francois said:

Hi I am using both at this stage and is busy change all my nodes over to the RFM69 and I don't have issue with range like I do with the NRS24L01+. I order my radio from Anadruino (http://www.anarduino.com/) to date I did not had any problems with the deliveries I get it relative fast. Also, it is easy to fit the radio on an Arduino mini pro see picture 1. Your footprint with the RFM69 is must smaller than it is if you fit the Arduino and NRF24l01 like I did with this LED dimmer and PIR Sensor see picture 2. The only problem I have at this stage is my power consumption is still high and I don't know why it is this high 3mA.

Picture 1:

Picture 2:

Francois,

What pin-mapping did you use? i.e. For each pin you used on the RFM69W, which pin on the RFM69W to which pin on the pro mini?

I have the parts, and I'm ready to wire one up. I'll try thinking it through from scratch, but it would be nice to compare notes also.

[Francois]

@neverdie I just using jumper wire to connect the radio to the Arduino mini pro see picture. This is working for me now as it is fast to get a sensor up and running.Also, it have a small footprint as well.

[NeverDie]

@Francois said:

@neverdie I just using jumper wire to connect the radio to the Arduino mini pro see picture. This is working for me now as it is fast to get a sensor up and running.Also, it have a small footprint as well.

Thanks! I've been wracking my brain, but for the cost in time and money I can't think of (or find) anything better, so I'm going to roll with what you did. A+

[NeverDie]

@Francois said:

@neverdie I just using jumper wire to connect the radio to the Arduino mini pro see picture. This is working for me now as it is fast to get a sensor up and running.Also, it have a small footprint as well.

@Francois
Thanks again for the photo. I recently wired this up using an RFM69W, not HW, and it seems to work.

However, I did find hat I needed to define pin D10 as an output pin using pinMode, or else it created aggravation. Setting it this way fixed that problem:
pinMode(10,OUTPUT);

I seemed to be getting unexpected current flowing through the DI00 wire, which seems to be connected to Pro Mini pin D2 (?) if I'm looking at your photo right. How are you initializing that pin in your code? Are you just defining D2 as an input pin, or is there more to it than that? Also, I'm guessing that at some point in your code you are attaching interrupts to D2?

[Zeph]

@Francois

The pin labeled "d00 irq2" looks like Arduino digital pin 2 (aka int0). Right?