nrf24l01+ with antenna problem

Question

I just got 4 nrf24l01+ modules with the external antennas, but I'm not able to make them work.

I'm using arduino nanos and MySensors to create a gateway and a sensor.

The funny thing is that when I put a antenna nrf as the gateway and a pcb nrf as sensor, they work just fine, but the other way doesn't.

I also tried two nrfs as gateway and sensor, but the behavior does not look good.

What could it be? Wifi router interference? Channel? Baud rate? Data rate?

Answer 1

It's likely an issue related to the modules' electric supply. The effects can be packet loss (even down to zero bps) or loss of communication with the module.

Two things have to be covered with the nRF modules for them to work:

• current draw (i.e. power),
• decoupling/filtering (i.e. bypass capacitors).

Since you don't mention specific devices, I'm assuming you refer to an 'antenna' module with SMA (or RP-SMA) connector.

The Nordic Semiconductor nRF24l01+ that is typically used in these modules has a maximum power consumption well below 100mW.

A module with power amplifier (PA) draws significantly more power than the nRF chip alone, the total power consumption will be larger than 100mW.

An Arduino can only supply power according to it's onboard regulator capabilities. The Minis (and Micros) feature a smaller regulator that cannot drive both the Atmel AVR microcontroller and the PA.

Solution:

• provide a separate 3.3V regulator for the nRF module(s),
• place a capacitor directly at the modules' connector's supply pins.

Link:

• https://arduino-info.wikispaces.com/Nrf24L01-2.4GHz-HowTo#PP