nRF24L01+PA+LNA

[wico2002]

Hi, i have the same problem. Bought a pa+lna radio with black antenna and only work if i touch the antenna or the radio's pcb, else the data if not sent at all. i added only a 200uf capacitor. Even with the breadboard power supply, to have a separate 3.3v it dont work. My basic nrf24l01+ is working well (except the range) but not the pre amplified one.

Any one have ideas ?

[Oitzu]

@wico2002 try adding a layer of plastic wrap followed by a layer of tin foil around the pcb.
In this process don't let the tinfoil touch the pcb or any connection. This will basically create a farraday cage around your pcb.
I've learned the hard way that the boosted modules can sometimes, at high power levels, interfere with itself.

[wico2002]

@Oitzu I try running it at a lower PA level, set in the code, don't know if it helped or not. I also found if I keep the antenna straight (my antenna plug is pointing on the side, so let say 0 degrees) or at 90 degrees no data is sent but if it is fold at 45 degree the data seems to be sent good even if I don't touch the radio (but still don't know if I got a good range or not). seems to work better without the antenna plugged in ...

i'll try your trick

[Oitzu]

@wico2002 that's all really the typical behaviour i observed, too.
In reality the module sends the data but will never receive the "ack" because the signal overloads, due to interferences, the nrf24l01+ on the board.
Holding your hand arround the pcb or antenna or unplugging the antenna weakens the signal and stops this behaviour.

See also: http://forum.mysensors.org/topic/1877/2-x-nrf24l01-pa-lna-with-rf24_pa_max/12

[wico2002]

Thank you for this link.

I will reply in that topic to continue the same subject.

[johnr]

Hi,

I built my serial gateway like two years ago and it is running smooth with nRF24L01+ PA+ LNA

I remember a had to fiddle with the power setting. Since I am now replacing it with a Ethernet gateway, I plan to use a ld1117v33 to power the radio. It can give 800ma so it should be suffcient to runt it without power issues.

Did anyone have experience with this? Do you recommend I should set Pa_level to high or Max?

[Oitzu]

@johnr you should give it a try. 800mA is more than enough.
But don't forget to shield the module probably otherwise you will have the above mentioned interferences.

Site note: The max setting is actually a special setting for nrf24l01+ clones that have a higher output setting on a special register then the original nrf24l01+ chips. But regardless the chip you can use this. A original nrf24l01+ will simply ignore the register flag.

[karl261]

@Oitzu Is that so? How could I find out if my nrf accepts the max setting? Maybe it is not using it at all. What is the default then? I also saw that @GertSanders was recommending to use the "high" setting as maximum. Maybe that is why?

[Oitzu]

@karl261 the MAX Setting is the HIGH setting + a extra bit. The extra bit is ignored by the original nrf24l01+ chips. Some nrf24l01+ clones (also known as the SI24R1) are using this bit to switch into a higher mode.

[karl261]

@Oitzu Ok, so, if I understand correctly, then, if I set the nrf to max, and it will ignore the flag, it will be at high, correct?

Another question: I have a battery sensor with a +pa+lna because I installed a little weather station in a bird house... Concerning battery life, would you run it at min or low?

[Oitzu]

@karl261 with the original nrf24l01+ modules this is correct, yes.
To save battery use the lowest setting that still works without transmitting errors.