NRF24L01+ doesn't like 12V powered nano

I have two NRF24L01-connected nano clones, Alice and Bob. Both are connected to their NRF24L01s using pins 9-13, 3.3V, and GND. Alice has an LED connected to pin 3.

When Alice is connected to USB, her NRF24L01+ is transmitting and receiving properly; Alice's LED blinks on and off in accordance with a signal from Bob.

However, Alice's LED fails to react to Bob's signal when Alice is disconnected from USB and connected to 12V through the Vin pin.

Troubleshooting I've already done:

The Blink sketch (modified to use Alice's pin 3) runs OK when Alice is connected to 12V. So the LED is good, and Alice is getting power.

If Bob's transmission software is loaded onto a 12V-connected Alice, The new AliceBob can communicate with other Alices that are connected to USB. So AliceBob's NRF24L01+ appears to be working OK under 12V, at least as far as transmitting is concerned.

A 12V-connected Uno with an NRF24L01+ and Alice's software has no problem receiving and reacting to Bob's signal.

Following instructions from this tutorial thread I have some 10 pF capacitors on the way but they won't arrive for a few days.

power supply
NRF24L01+
nano clones

Any advice or ideas while I wait for my capacitors to arrive? Thanks in advance.

The problem may be that the voltage regulator is overloaded when stepping down from 12v.

I have come across other Threads in which it seemed that a Nano cannot provide enough 3.3v current for an nRF24 - so maybe it is marginal and you are lucky with one of them. Try powering the nRF24 from a pair of AA alkaline cells (3v) with the battery GND connected to the Arduino GND.

And you need 10µF capacitors, not 10pF.

...R

Robin2:
The problem may be that the voltage regulator is overloaded when stepping down from 12v.

Thanks Robin2; I ran the 12V input through a buck converter and supplied Alice with 9V through Vin. Alice is responding appropriately to Bob's signal now.

The amount of knowledge contained in this forum never ceases to amaze me. Thanks again, I'm truly grateful.

jrodda:
Thanks Robin2; I ran the 12V input through a buck converter and supplied Alice with 9V through Vin.

You could also use an external 5v regulator and power the nano though its 5v pin.

...R