Which are the *best* NRF24L01+ modules?
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Yup, same as before. The measurements on the blob module are:
-43.3ua and -42.8ua.I'm not sure which is standby current and which is sleep current. I definitely was not expecting a negative current. There's not much difference in magnitude between the two currents.
So, I tried it on a different blob module:
-43.5ua and -42.9ua.
Essentially the same results.Truly bizarre. What's going on? I'm powering the Uno through a roughly 9V battery pack of Eneloop batteries via its barrel jack, as with the earlier measurement of the Itead module, whose measurements not only met expected value, but they were positive currents, not negative ones.
Here's the red module:
Powered Down (Sleep): 1.6uA
Standby: 13.9uAHere's an Addicore module from Amazon:
Powered Down (Sleep): 1.8uA
Standyby: 16.3uAIt's a very simple test. I'd say anyone can do these measurements, provided they have a good way to measure microamps.
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@NeverDie said:
-43.3ua and -42.8ua.
So the blob module is so good that it is charging your batteries ;-)
@rvendrame said:
@NeverDie said:
-43.3ua and -42.8ua.
So the blob module is so good that it is charging your batteries ;-)
I'm measuring the current between the Uno 3.3 Female header pin and the Vcc pin on the RF module.
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Now talking seriously, maybe the some current is leaking through the other pins (MISO, CE, CS, etc), from arduino to radio? That would could an negative VCC flow I think...
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It must be that. I wonder how it would measure if I were to use 3.3v on the datapins rather than the 5v the Uno uses.
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In theory it would require a logic level converter
But for sure the atmega is tolerant between 3.3V and 5V. And probably the converter would introduce an error in the u-measurement, I guess.
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I plugged a blob module into the RFToy, which is effectively an 8Mhz Mini Pro running at 3.3v, and used a jig similar to the one before (just no resistor) to route the module Vcc current into the uCurrent.
This time it is powered through the USB port, and the voltage is downshifted from there.
New measurements for the blob module:
Powered Down (Sleep): 3.3uA
Standby: 67.2uAFor comparison, I plugged the Itead module (Nordic tracecode 1301CL) into the same apparatus, and this time I got
Powered Down (Sleep): 0.6uA
Standby: 22.8uA
which, within measurement error, I would call the same as when it was hooked up to the Uno. -
@Zeph: For the NRF24L01+ modules, I now have good enough current measurements that I wanted to get, so I'll be holding off on doing further measurements, at least for now. I want to try the RFM69HW for comparison, but that is outside the scope of this thread.
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BTW, using just my Fluke 87V multimeter set on the uA setting, the measurements I get are:
Fluke 87V Itead Module Measurements:
Powered Down(Sleep): 0.5uA
Standby: 22.5uAand
Fluke 87V Blob Module Meaasurements:
Powwred Down(Sleep): 3.0uA
Standby: 56uAand
Fluke 87V Addicore module from Amazon Measurements:
Powered Down: 1.2uA
Standby: 18.2uASo, although a bit different than the uCurrent measurements, they seem good enough for separating out the fakes that I have from the genuine article (which at this point the evidence suggests is what the chip in the Itead module is).
So, good news! Maybe all you need is a DMM with decent uA measurements. If I'd had this information at the very beginning of this thread, it would have saved me a lot of frustration and doubt. Now everyone can be empowered. :smile: The next time you buy modules, you can now easily test them right away and send them back if they're fake! :smile: :smile: :smile:
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BTW, using just my Fluke 87V multimeter set on the uA setting, the measurements I get are:
Fluke 87V Itead Module Measurements:
Powered Down(Sleep): 0.5uA
Standby: 22.5uAand
Fluke 87V Blob Module Meaasurements:
Powwred Down(Sleep): 3.0uA
Standby: 56uAand
Fluke 87V Addicore module from Amazon Measurements:
Powered Down: 1.2uA
Standby: 18.2uASo, although a bit different than the uCurrent measurements, they seem good enough for separating out the fakes that I have from the genuine article (which at this point the evidence suggests is what the chip in the Itead module is).
So, good news! Maybe all you need is a DMM with decent uA measurements. If I'd had this information at the very beginning of this thread, it would have saved me a lot of frustration and doubt. Now everyone can be empowered. :smile: The next time you buy modules, you can now easily test them right away and send them back if they're fake! :smile: :smile: :smile:
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All's well that ends well. :smile:
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BTW, I just now measured this surface mount module using the uCurrent, and it measures out at
Powered Down (Sleep): 0.7uA
Standyby: 22.7uA
Therefore, I deem it genuine. I got it at ICStation two or three months ago:
http://www.icstation.com/nrf24l01-rfid-wireless-transmission-module-2dbm-p-4620.htmlIt would help a lot if others here, when you measure your module, would post your measurements and where you got it from, and when. That way we can all benefit from the network effect and make better purchases and possibly avoid bad purchases also.
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Hmm.. no.. but I cannot for my mind recollect where I could have read it. So it might just have been a creation of my (weird) mind. :)
Er, check the second sentence of the first (real) paragraph of the OP of the earlier fake nRF24L01+ thread.. Maybe that's where @hek got that impression.
And now I am the one who doesn't recall exactly where I read that - but it's undoubtedly from one of the sources I linked to in that post, raised as one of the reasons to be concerned about fakes.
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Those with a low idle/sleep power usage are either Nordic or a quality clone.
Even the blob modules would be workable in non-battery nodes, if they indeed have excellent range and low packet loss.
So I just looked up the Fluke 87V, and the price is a bit high for my budget. So alas, the current state of our fake detection (pun acknowledged) is not a universal solution.
Perhaps a variant with a coulomb counter will arise. Or perhaps using the 200x amplified differential ADC input of the Leonardo or Mega2560 with averaging.
And I think it would be very apropos to distill the knowledge from these many posts into a wiki page. As with many threads here, there's some great info but sometimes it's embedded in hours of reading to find it again.
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@NeverDie - now that you have the measurement down, how about measuring receive current, and perhaps carrier-only transmit current? Both of those can be steady state.
I'd still like to know how the various models rate in those areas too, while you have the setup handy.
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@NeverDie - now that you have the measurement down, how about measuring receive current, and perhaps carrier-only transmit current? Both of those can be steady state.
I'd still like to know how the various models rate in those areas too, while you have the setup handy.
