High Power NRF24L01 modules not functioning properly due to antenna-suggestions?

Hello Everyone

Wishing you all a wonderful 2016. I've been working for a while now with the NRF24L01 modules, the low power ones specifically - link to model.

With this I've used the NRF24L01 Socket Adapter - Link to model.

I've used the socket adapter to rule out any power problems that I thought I had when I started working with these modules. I then acquired some of the high power NRF24L01 modules - Link to model.

My program worked well with the low power modules but I ran into trouble with the high power modules. The trouble I experienced was that the signal would not be received from the transmitter to the receiver or the signal would not be relayed to another node when the antennas were attached. Initially I figured that the modules was faulty because with the low power modules they worked fine. This is with all the units within 3 ft / 1 m range of one another. Then I removed the antennas and the high power modules also worked fine. (Rubber duck antenna provided with the unit - The units that I've purchased was from Alibaba so not from Seeedstudio as per the link)

I found that whenever I touch the antenna then it works perfectly. I've had some additional antennas lying around which I switched with the ones that came with the radio modules. This seemed to solve a lot of my problems, unfortunately I didn't have too many extra antennas lying around so I was hoping that someone had some insight as to whether I can apply additional soldering to the inside of the antenna at a certain point that might "fix" the antennas to resolve the problems I'm having with them?

Any input would be greatly appreciated. I've based my code on Mcnobby's code - link to post with code - since I required more hops then the RF24 network library allows for. Thanking you in advance.

Regards
Dirka

Hi,
The high power units draw more current than the low power units, the socket adapter will not fix your problem unless you increase the size of your supply.

What are you using as the supply for the high power units?

Without an antenna the high power units do not draw as much current as when the antenna is attached, it is a general rule in the RF world you do not drive a transmitter without a load/antenna.

Tom.... :slight_smile:

Hello Tom

Thank you for the feedback, I didn’t realize that the module would draw more current with the antenna attached.

I’m driving the units with a Vantec 7 Port USB hub, I was driving 7 units with it last night. The hub’s maximum output current is 3 A so 3000 / 7 = 428 mA per port.

Each USB port drives a Arduino Nano. A socket adapter is connected to the 5V supply from each Nano. A high power NRF24L01 is then connected to each socket adapter. According to this website, the maximum current draw of the high power NRF24L01 is approximately 150 mA.

The socket adapter uses a AMS1117-3.3 to generate a 3.3 V signal from the the supplied Vcc and can deliver a current up to 1 A. I do also realize that this voltage regulator on the socket adaptor will never be able to source 1 A of current due to the USB port that can only source up to 428 mA but since the module shouldn’t draw more then 150 mA I believe that the supplied current should be enough.

Last night I actually switched out the antennas on the units that would not receive and transmit and I was able to relay my signal through 6 relay nodes (using the high power NRF24L01 modules with antennas) from a transmitter to a receiver so this further leads me to believe that the power I am supplying should be enough (Still connected to the USB hub).

Do you perhaps think that I got lucky with these antennas or do you have any other thoughts or suggestions? Thanks Tom really appreciate it.

Bear in mind that it is also possible to overload the front end of a receiver, if the transmitter is too close. Some receivers are protected against this, but not all.

Thanks for the feedback jrdoner

I thought about this as well. I also just thought that maybe my antennas weren't orientated to be within the radiation area of one another, that might also be a problem since it was positioned horizontally and not vertically. I guess that I will have to test again when I have the modules outside and have some space available.

Thanks for the feedback guys and if you can think of anything else please let me know. Wishing you a wonderful day / evening ahead.

Regards

Dirk