FEZ Panda and Arduino Connected with Nordic nRF24L01+

I have a Panda 1 that I am attempting to wirelessly link with an Arduino. I’m using the maniacbug RF24 libraries for the Arduino, and Gralin’s libraries for the Panda. This setup works well using the low power version of the Nordic RF24 (http://arduino-direct.com/sunshop/index.php?l=product_detail&p=188). The two units exchange messages with no problems.

I switched the low power units out for the high power units (http://arduino-direct.com/sunshop/index.php?l=product_detail&p=190), and added a separate 3.3V power supply to satisfy the higher current needed by the high power unit. The VR for this power supply can provide up to 800 mA. When I switch to the high power RF24’s, no messages are received by the Panda. I added an external power supply to the Panda (in case the USB couldn’t provide enough current), but this does not help.

My questions are:

  1. Is there a difference, other than the power requirements, between the high power and low power version of the RF24 that I need to account for in the library?
  2. My understanding is that if a circuit is drawing more current than can be supplied, the voltage from the power source will drop. Is that correct?
  3. How do I change the data rate in the Gralin library? I noticed that the SPI data rate is set to 2000 KHz in the library. Will changing this data rate be sufficient for changing the data rate for the wireless module?

Any help will be greatly appreciated!


check this out:

so are you able to use the mesh part of Maniacbug ?

i’m interested to see how you’ve got that working… please share…


Richard -

Nice work with the nordics!

Just a quick soapbox type note about where you get your hardware. The guy who supposedly runs YourDuino.com, Terry King, is a very shady dude. So shady, in fact, that I’m not sure he is even a real person. A recent email interaction with him led me to discover he promotes counterfeit Arduino Unos, seen here http://arduino-direct.com/sunshop/index.php?l=product_detail&p=3 . He was attempting to muscle his way into our local maker faire, I think to sell stuff, but the SoapBox Police (me) are onto him.

Please don’t support any company that blatantly violates trademark law like this. It’s one thing to value add some features to the Arduino Uno and open source hardware community in general. It is another entirely to rip off a design to make a buck. See this (Soapbox: Counterfeit Open Source Hardware — Knockoffs 101 - Make:) article to get a better idea of what I speak of. You’ll note a picture of the YourDuino board in this article. My mission is to educate folks about this less than honest use of the OSHW movement.

That said, it looks like the “reputable” site I’ve used to buy Nordics in the past is out of the long range ones.

Thanks for taking my current cause into consideration!

Sargent Soapbox (aka Eric)

Here is where I got mine from

Jay Jay - thanks for the link. I might not have read enough of the thread to pick this up, but were you able to successfully change the data rate using the register value change in the thread you linked?

Also, my setup is very simple: one sender, one receiver in a command/response type of protocol. It sounds like the mesh setup would involve multiple senders/receivers, and i don’t have any experience with that (yet!).

ransomhall - thank you for the warning about yourduino.com. Stealing other people’s IP is a rotten thing to do!

After some more futzing, I found out that the Panda was not the problem. In the Arduino code, I was only doing a startListening command if the previous Send command was successful. This resulted in me invoking a stopListening command when the device was already in that mode. Fixing the missing startListening command resolved the problem and the setup is working perfectly now.

Thanks to both of you for your help!


Glad to hear you got it working…

without Gralin’s gracious driver gift, none of it would have been possible… SO THANK YOU GRALIN.

1 Like

You are welcome :slight_smile: I hope someone will like to contribute to that library or to the codeplex site :wink: Now when we seem to understand how those modules work this library could be written a lot better!