Which are the *best* NRF24L01+ modules?
-
it looks like the blob-one is missing some SMD components. ;-)
Are you able to measure the performance in long-distance (or maybe with walls in between)? The 250kbps should perform better --- in theory....@rvendrame said:
it looks like the blob-one is missing some SMD components. ;-)
Are you able to measure the performance in long-distance (or maybe with walls in between)? The 250kbps should perform better --- in theory....Yes, I've done that test already using a pair of Addicore modules. For that test setup, I got 30% packet loss at 250kbps, 87% packet loss at 1mbps, and 100% packet loss at 2mbps (not even a single packet got through). For the packets that did survive the round trip, the average round trip travel times (using an 8Mhz Arduino to echo it back) were 2.8ms for the 250kbps datarate and 3.5ms for the 1Mbps datarate. I'm not sure why the roundtrip time was less at the 250kbps datarate, unless ithe round trip times reflect a lot of retries that the modules are doing without my specifically directing it. The maximum number of retries would have been whatever the default is, because I never set it (though perhaps the Mirf library did so without me being aware of it).
It was when I tried doing that test with a pair of blob modules that I realized they couldn't be using genuine NRF24L01+ chips, because they lacked the 250kbps capability..
-
Maybe this will be of interest http://forum.mysensors.org/topic/1345/sensebender-micro/228
-
I ordered 3 NRF24L01+ modules from an Itead distributor named EpicTinker. The units arrived each in their own individual box:
Inside the box was this:
Inside the sealed packaging was this module:
Here's the back of the same module:
I ran a ping-pong test, as I had done with other modules, and at 1mbps in the same location, after sending 88,000 packets, the packet loss rate was 99.8%, and the average round trip time was 3.75ms.
So, a worse rate of packet loss and average worse round-trip time than with the addicore's I described above.
So, is it a bogus chip, or is the module layout bad, or....? Does the packaging match what others are receiving from itead directly?
-
@NeverDie Probably the best indication of real vs. counterfeit is the laser marking on the IC:
One on the right is genuine.
Especially the '+' sign is different on both markings -- it has a 'hole' in the center on the genuine one.Yours seems to be solid too...
Possibly it would help if we start composing a list of all versions encountered 'in the wild', including register dumps and fotos and try to find a common identification for genuine/fake ones.
-
Yes, module from EpicTinker looks relatively solid in the '+', and the dot is visibly hollow:
So, does that mean it's a fake?
Also, I notice that in the two chips you compare side-by-side, the "1" font is definitely different.
-
Also, I notice that on your genuine board, the discrete component below the chip has the value 105 (or is it 501?), whereas on mine it says 01E. That's different. Is there such a thing as an 01E?
-
This is a genuine Nordic module. Not easy to see the hole in the cross.
Here is some misc module I bought from ebay:
Here is an amplified module of mine.
@hek said:
This is a genuine Nordic module. Not easy to see the hole in the cross.
Here is some misc module I bought from ebay:
Here is an amplified module of mine.
Have you observed any difference in the performance of the three different modules that you have? The module in the middle photo has the "1" font discrepancy noted above.
-
@hek said:
This is a genuine Nordic module. Not easy to see the hole in the cross.
Here is some misc module I bought from ebay:
Here is an amplified module of mine.
Have you observed any difference in the performance of the three different modules that you have? The module in the middle photo has the "1" font discrepancy noted above.
-
@Yveaux said:
That's why I suggest we join forces and start collecting data to discover some patterns to distinguish fakes from genuine!
I 100% agree. That's why I'm posting as much info as I can. I hope others will do the same, as it is in our common interest.
In my testing to date, at 1Mbps the blob modules vastly outperform the allegedly Itead modules. The question is: what can I attribute that to? I won't ever be buying anything more from Itead or any of its distributors until after this gets resolved.
-
I just now opened up the third Itead module to see if it was any different. Lo and behold, it is:
This may be the strangest chip yet. Rather than a dot above the N, it looks like a rectangle. In addition, there's some plastic nub of some kind above the R. Lastly, the "1" font seems more similar to the allegedly fake chip than the chip Hek thinks is genuine.
So, I just now ran the ping-pong test on it, and it performs even worse than the allegedly Itead modules I photographed earlier. When ping-ponging with one of those, the percentage of lost packets is 99.92% out of 90,000 packets.
I don't know what to make of all this, but it doesn't look good.
-
The nub almost looks like a 3d variant of the Nordics logo. Have they done this to make it harder to copy/clone?
Are you using the same type of chip on both ends? I imagine intercompability could be an issue when mixing different fake once or with genuine chip.
-
The nub almost looks like a 3d variant of the Nordics logo. Have they done this to make it harder to copy/clone?
Are you using the same type of chip on both ends? I imagine intercompability could be an issue when mixing different fake once or with genuine chip.
-
@hek said:
Ok, 99.92% packet loss is extremely bad. Are you sure you're giving it enough juice?
Good question. What I've done so far is plug them into a couple of RFToys:
so they're getting as much juice as the RFToys are giving them.
I've been assuming that an RFToy would give them enough juice, but maybe that's a faulty assumption.
-
OK, for easy testing, I just now ordered some socket adapters:
and should receive them on Tuesday. Also, instead of RFToys, I'll try driving them from Arduino Mega2560's. Does anyone here have experience to know whether the socket adapters will supply sufficient juice? I would hope so, as it would seem to be its primary function, but if anyone knows for sure one way or the other, please post.
Meanwhile, I may try powering the modules using bench power supplies.
