Frequency hopping experiments on the NRF24

Any old or new electronic projects on the go
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RichardT
Posts: 18
Joined: 03 Mar 2019, 17:15
Location: Surrey

Re: Frequency hopping experiments on the NRF24

Post by RichardT »

At last I have 3 'plus' 250kbps rf-nanos :D , return postage refunded, and 3x 1mbps versions to play with. I can't really fault Keywish, they did sort it out in the end. Hopefully our efforts have saved others some time.
bluejets
Posts: 316
Joined: 19 Jun 2019, 04:09

Re: Frequency hopping experiments on the NRF24

Post by bluejets »

Tobe wrote: 13 Sep 2020, 06:10 PM for how many you need as i might be able to help you there
Thanks but I guess I will work it out one day, no rush at the moment.
For an update, still cannot get what I want.
It seems for some strange reason that there are something like 9500 plus of these things in stock BUT they will only sell me one.
Never used this Aliexpress before so maybe that is the reason, this seems crazy though.
In reference to the image enclosed where I signed in and selected the required model, the numbers area is greyed out and I cannot change the number I need anywhere, even after going to the checkout.

(1 piece at most per customer) ...????????..strange way to operate a business...

Thought it could be to do with this low price special but I cannot get past that either.
I find ones for $3 to $5 odd but they keep flicking back to this "special price" one at one off only.

Just thought I'd include the details here for others that may have the same problem but sadly no answers.
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Tobe
Posts: 665
Joined: 16 Feb 2018, 06:19
Location: Varberg or Stockholm, Sweden

Re: Frequency hopping experiments on the NRF24

Post by Tobe »

It looks to me that first you have to take advantage of the new customer deal after which you should be free to order as leisure! Just for the sake i opened a new account under my son's name and his postal address and encountered your issue.
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Cheers,

Tobe
bluejets
Posts: 316
Joined: 19 Jun 2019, 04:09

Re: Frequency hopping experiments on the NRF24

Post by bluejets »

Ok...thanks Tobe.

Like I said, strange way to do business .... :(
Tobe
Posts: 665
Joined: 16 Feb 2018, 06:19
Location: Varberg or Stockholm, Sweden

Re: Frequency hopping experiments on the NRF24

Post by Tobe »

....I'm more than happy to ship you a few if you tell me how many you need and PM a post address to send you a few
Cheers,

Tobe
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Phil_G
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Joined: 15 Feb 2018, 23:32
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Re: Frequency hopping experiments on the NRF24

Post by Phil_G »

I've been testing a 'screened' version of the NRF24L01+PA+LNA and it appears to be a significant improvement over the previous 'open' versions. After finding a few NRF+PA+LNAs intermittently misbehaved at full power, I did some interweb digging and apparently its not uncommon - I found several reports where on full-power it seems to 'swamp itself' with stray RF and hand-shielding improves the throughput... I've found that either kitchen foil or groundplane wires improve it, but the troublesome ones seem to 'misbehave differently' :D so its hard to pin it down to one 'cure-all' solution. I should emphasise this is only on a few random NRF+PA+LNA chips, not all by any means.

These shielded ones appear to be perfect, they do 250kbps, they're unaffected by the presence of hands, metal cases, close rx proximity, etc - AND - they have an FCC approval stamp!
They also claim to use genuine Nordic chips :D Theres no easy way to tell if this is actually the case.

IMG_20200922_194511.jpg


I've tried them at 1mbps and 250kbps with no problems whatsoever. They are connected exactly the same as the previous 'open' PCBs so the standard 'power adapter' thingy fits perfectly, just plugs in. They do look as though they're made to a higher standard - and all the SMA connectors are perfectly square - some of my early NRFs look quite roughly made and have SMAs that are not quite true.

They were a bit more expensive at £2.50 but thats still cheap in my book when Frsky want £45 for a hack-module. Heres the Aliexpress link I used, I think I'll order some more.
https://www.aliexpress.com/item/4000132850562.html


IMG_20200922_191902.jpg
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Wayne_H
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Joined: 17 Feb 2018, 05:26
Location: Temora, NSW. Australia
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Re: Frequency hopping experiments on the NRF24

Post by Wayne_H »

Thanks for the heads up Phil. This is a great way to reinvigorate(?) many of my (still in boxes) older sets cheaply and reliably. :D The same seller also has a "5 pack" with a reduced unit rate & postage:

5pcs nrf24l01 E01-ML01DP5 Ebyte Long Range 2100m SPI NRF24L01+PA+LNA 2.4GHz RF Wireless Transceiver Module Antenna with Shield
https://a.aliexpress.com/_msqzLYn

I've just ordered a pack of 5.
Cheers,

Wayne
Once a Retrobate, always a Retrobate............ ;)
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tiptipflyer
Posts: 393
Joined: 16 Feb 2018, 22:49
Location: Germany

Re: Frequency hopping experiments on the NRF24

Post by tiptipflyer »

Thanks guys, I will order some.
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Phil_G
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Re: Frequency hopping experiments on the NRF24

Post by Phil_G »

If you remove all the pins, then refit two on the screened side, Franks regulator idea still works:

IMG_20200923_110813.jpg


You could leave the two power pins in place and mount the regulator on the rear:
Either way, do the wiring first, then mount the regulator as it obscures the holes!

IMG_20200923_113239.jpg

Either way this makes the complete unit much smaller than the "original+power adapter" version:

IMG_20200923_111622.jpg

Heres the finished, heatshrunk module ready to install:

new_modules.jpg


Wiring is as per the 'old' DIY-More Strong diagram:

nrf24l01_highpower_minireg.jpg


I've made up three screened transmitters now, all behave perfectly - whilst transmitting you can shroud them, handle them by holding or cupping the aerial, holding the SMA base, you can put them in a plastic or a metal enclosure with the SMA grounded or not - nothing phases them at all, the receiver traffic indicator LED shows 200 packets per second regardless. I've not fitted any extra capacitors, they dont seem to need it. This may well be another Eureka moment :D
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Mike_K
Posts: 669
Joined: 16 Feb 2018, 06:35
Location: Hertfordshire

Re: Frequency hopping experiments on the NRF24

Post by Mike_K »

If you want to see the FCC report details:

https://apps.fcc.gov/oetcf/eas/reports/ ... =2ALPH-E01

So Phil, your transmitter modules appear to be legal in the USA while the OrangeRx DIY modules aren't! I've emailed Ebyte asking what EN are covered by the CE mark and if it has been independently tested and quickly received an email (not computer-generated) saying it was being passed on to their technical department. It also said they have an official Aliexpress store, but I notice an antenna is not included. Some resellers may sell cheaper, but you're guaranteed to get original parts from the official store:

https://www.aliexpress.com/item/4000516 ... hweb201603_

https://www.aliexpress.com/item/4000185 ... hweb201603_

Cheers Mike
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