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Project Notes

#187 nRF24/PingPong

Two Arduino’s entertaining themselves with a game of “ping pong” over nRF24L01+ 2.4GHz RF.

Here’s a quick video of a “game” in action:



This is a quick first test of Arudino 2.4GHz RF communications using nRF24L01+ modules.

I’m using the maniacbug/RF24 library and the code is based on examples provided.

The PingPong.ino script runs on both the “ping” and “pong” node. A ground link on pin 8 tells that aRduino to play “pong”. Here are the rules of the game:

  • “ping” serves: sends a packet and flashes its LED if successful, and waits for reply
  • “pong” receives the message, flashes its LED and sends the message back
  • if/when “ping” gets the reply, it waits a bit and starts again (else logs an error before restarting).

This is not really stressing the communications, but a nice way to prove the basics are working.

NB: I’m using these nRF24Breakout modules to make it easy to breadboard the circuit.


See the schematic for details. Here’s the summary of pin connections to the nRF24L01+ module:

Line Arduino
3V3 3V3
CE 9
CSN 10
SCK 13


According to the datasheet:

  • 1.9 to 3.6V supply range
  • 5V tolerant inputs (5.25V max)
  • 60mA maximum power dissipation; 13.5mA RX at 2Mbps air data rate

That’s almost perfect for driving with an Arduino Uno, with the exception of the maximum current draw:

  • 5V GPIO pins are acceptable
  • 3.3V pin is within the voltage supply range
  • the Arduino specifications state a 50mA limit for 3.3V Pin

But I’m going to chance it for a quick demo, as many others seem to have done quite succesfully. For a fixed installation, I think I would provide a stiffer external 3.3V supply to avoid overloading the Arduino’s onboard regulators.

In practice, I’m seeing no more than 14.8mA drawn by the nRF24L01+ module (send or receive).



The Schematic

The Build

Credits and References

Project Source on GitHub Project Gallery Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is just my personal collection of projects. Two main themes have emerged in recent years, sometimes combined:

  • electronics - usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting
  • scale modelling - I caught the bug after deciding to build a Harrier during covid to demonstrate an electronic jet engine simulation. Let the fun begin..
To be honest, I haven't quite figured out if these two interests belong in the same GitHub repo or not. But for now - they are all here!

Projects are often inspired by things found wild on the net, or ideas from the many great electronics and scale modelling podcasts and YouTube channels. Feel free to borrow liberally, and if you spot any issues do let me know (or send a PR!). See the individual projects for credits where due.