Nanode RF

Hi All,


New to the Emon TX and Nanode....


Have a question in relation to the RFM12B and the nanode - I have the EmonTX built and tested, but am confused with the nanode and the RFM12B.


Basically, I have what appears to be the new build (a red PCB no 0988). I don't have the Jeelabs RFM12B, but do have an additional RFM12B identical to the one with the EmonTX.

Firstly, is the modification to the nanode (encj pin 4 plus resistor) still required with this new board. Also, do I need the Jeelabs RFM12B adapter board?

It seems to me via the schematic that I can use the 3.3v supply from the Nanode to power the RFM12B - and connect the data lines in the same way as they are connected on the emonTX - so thus why would I need to continue using the resistors on the jeelabs board?

I hope I'm making sense...

Or another way of asking it would be  - is the nanode 5v or 3.3v - it loks like 3.3v all across the board derived from the 7805 regulator and the 3.3v regulator.


Thanks in advance.




glyn.hudson's picture

Re: Nanode RF

Hi Gerard,

The JeeLabs RFM12B breakout board is not essential to connecte the RFM12B module to the Nanode. It just makes the connection process relatively straightforward and tidy.

Yes the modifications as detailed on the Nanode Wiki are still required when not using the RFM12B board. The RFM12B will still be connected in exactly the same way. 

Yes, your correct the RFM12B module can be powered by th Nanode's 3.3V power supply. This is why we suggest not soldering in the 3.3V regulator on the RFM12B board as seen in the photo on

As you know the RF12B should not be opperated at 5v, the level shifting resistors are required to convert the 5V singnal from the Nanode to 3.3V as to not damage the RFM12B. The Nanode natively runs at 5Vsupplied by the 7805 requlator (if using an external supply). The ethernet chip on the Nanode runs at 3.3V, the tri-state buffer chip is used as a communication buffer between the two chips. 

A new Nanode board called the NanodeRF is due to be released next month. The Nanode RF runs natively at 3.3V and has a RFM12B onboard. Follow Ken Boaks blog and twitter for latest updates: The NanodeRF will solve a lot of the compliations regarding adding an RFM12B board to the Nanode.

If you do wish to connect your RFM12B module directly to your Nanode you might find the information on this page useful:

All the best, Glyn

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