nRF24L01+ missing capacitor aka "magic finger"

[ben999]

Hello Everyone,

I love my MySensors + openHab setup but it gets really frustrating when a node just stops working for a while... and then comes back on track a few hours later.

So, long story short : i was just about to switch to (and order some) RFM69 modules last night when i discovered the "magic finger trick" (as i was looking for power consumption nRF vs RFM).

Looks like a pretty high number of nRF modules left the factory with a missing capacitor...

https://ncrmnt.org/2021/01/03/nrf24l01-fixing-the-magic-finger-problem/

Is it just me and everyone else knew ? ALL mt nRF24s from various suppliers are missing that capacitor... no wonder then (if that's the real culprit) !

So I have just ordered a batch of smd capacitor... i'll let you know.

[Honk]

Just looked at my modules and the capacitor is also not there. Only on my ebyte module
https://www.cdebyte.com/Uploadfiles/Picture/2021-12-21/202112211521171309.jpg

this Module seems to have the capacitor to ground in place. There are more expensive and I used them when the cheap ones did not work.

[ben999]

@Honk thanks a lot for your input

I'm building @AWI 's "connection quality meter" so i can quantify any change. Being a 10 year's experienced noob in MySensors, it takes me for ever to get it right :D

Please share your experience with faulty modules in possible connection with that missing capacitor.

[TheoL]

@ben999 I've been running my NRF network for over 10 years. They all have 100uf Capacitors - maybe a bit high - but besides some range problems it is stable.

Although because of the limited range, I'm switching to rfm69 radios.

[ben999]

@TheoL thanks a lot for your message.

But i guess you are talking about the additional capacitor, in between 3.3V and ground ?

What i would like to know is if these modules you're using do have a 1pF capacitor as per picture :

Please let me know !

[TheoL]

I grabbed one from the stock. And it the part you circled only has solder dots, no capacitor.

[ben999]

@TheoL thanks for reporting back.

In case you haven't ordered RFM modules yet i could send you a handful of capacitors to update your nRF modules... how about that ?

I have ordered a hundred... well over a lifetime of 1pF capacitors for me :D

[TheoL]

@ben999 Thank you for the offer, but honestly I have been hand soldering SMD for the last few days true a magnifying glass. And I cursed a lot lol.

I will have two networks. NRF for inside the house and RFM for the outside.

I'm curious however how it will work out. So keeping an eye on this log.

What is the mount size of those capacitors. 0805 with a magnifying glass is kinda doable. But I don't think I can do smaller without having to buy a digital microscope

[ben999]

@TheoL 805 package measures 2x1.2mm... :D depends on your visual acuity !!

Two netwoks with seperate GW ?

[TheoL]

@ben999 Yes I have 3 gateways 1 nfrf and 1 rm for production. And 1 nrf gw for test. The test gw is on a separare PI

I might run a 4th gw. Also an rfm on the test machine.