Nrf24l01+ problem. ( Works only when touching the pcb antena)

Projects Networking, Protocols, and Devices
1

Hi everyone,
It's been few days now, I'm "fighting" with the Nrf24l01+ modules (black pcb, with pcb "zigzag" antenna) but without success.

Actually all my Nrf24l01 modules (15pcs) that I have tested with 4 different Arduino 3.3.V, 8 MHz Pro Mini, mounted on breadboard works guite well and i get solid connection between transmitter and 2 receivers. Also Nrf24 maniacbug library "scanner" sketch shows my home wifi connection, working microwave ans other 2.4.GHz devices with.

Hoever, when I solder same tested modules to custom PCB , which actually a copy of arduino mini pro 3.3.V, 8 MHz, but with I2C OLED display, i can't get it to work correctly.

No matter which sketch I use, the signal is very weak, with ractically 95% of packes loss even at 30cm 2m distance.

"Scanner" sketch shows very little of data, with 90% of Zeros and low signal (shows very few digits between 1 and 3)

But when I touch the module's pcb printed antenna I get stroner signal, which is however 40-50% weaker compared to the same module mounted on breadboard.

Arduino is powered from 3.7v LiPo 1000mAh battery.
NRF24L01 module and OLED are powered trough 3.3V 250mAh voltage regulator.
There are 0.1uF + 10uF capasitors on voltage regulator output pin.

I have tried to add: 0.1, 10, 100 uF capasitors between nrf24l01 3.3v and groung pins, with almost no changes.
PCB tracks length from Atmega 328p-au to module is 30-40 mm.

The voltage regulator's output volage is 3.29v and seems to be very stable.

The setup is same as on breadboard, but doesn't works :confused:

I'm getting tired to pull my hairs off...

Any help will be appreciated.

2

I forgot to say, that Nrf24l01 modules on breadboard works much better without any decoupling capacitor between 3.3v and groud pin. But on custom PCB, capasittor (or without) makes almost no difference.
With the breadboard setup I got good transmission range about 100-130m outdoor, with 2-5% packets loss. Tested on Lyon city's (France) center street with lot or parked vehicles on both sides of the street, but almost without people.

Indoor I get only 6-9 meters trough one vibro-concrete wall.

With my custom PCB hoever it's a different story. I got very weak signal, and only when touching the pcb etched antenna with finger.
If I solder the SMA wifi antenna to Nrf24l01 I get better result than with my fingers, but weaker than the setup on breadboard.

Also here are few aditional details about the programming:
In both cases , in my sketches, I'm using 250Mbit transmission speed, auto acknowledge enabled, payload size 8bit, and default PA level.
"Scanner" sketch settings are without any changes.

Regards.

3

hi. Didi you got it working and fond the problem?
I am having same kind of problem here. I etched custom PCB including ATmega 328-pu nokia 5110 lcd and nrf24l01+ module. I did not have much time to test it the other day but I continue working tomorrow.

4

You have re-awakened an 18 month old Thread which never got any Replies even when it was young.

I have had no problem getting nR24 modules working with Atmega328s on strip board and with an Attiny1634 without any PCB.

Have you been able to get your nRF24s working with regular Arduinos? That should be an essential first step.

If your nRF24s work with regular Arduinos but not with your PCB versions then post a schematic of your PCB version. Also post a photo of your PCB version so we can see the physical layout.

Do other Arduino programs work properly on your PCB version?

...R
Simple nRF24L01+ Tutorial