Emon Tx V4 and 433MHz Radio Formats

I was wondering how many RF data formats there are at the moment? I have some questions, and as I am a bit confused, | would be grateful for any help!

As far as I can tell, there are three named versions:

  1. Jeelab (called classic or legacy)

  2. rfm69n (used when running emonLibCM on the original emonPI, with compatible versions available for other units) see
    The emonPiCM

  3. LowPowerLabs RFM69 (available in the emonTx V4 and the current emonBase)

Is this correct?

Are any of them compatible?

If I want to have a system of an original emonPi (running emonLibCM), an emonTx v4 and an emon Tx V3, which format should I use, and is firmware available for all the various devices?

A format versus device versus available firmware matrix table would be useful.

Sorry for all the questions!

I apologise if this is all documented somewhere and I haven’t found it!



As far as I’m aware, yes.

Hardware-wise, all are. Software-wise, none are.

“rfm69n” is properly called JeeLabs Native.

This might help:
Radio Packet Formats.pdf (14.9 KB)

Thats a nice format comparison, thanks @Robert.Wall

I will be releasing LowPowerLabs firmware for the emonTx3 and emonPi soon, so I would advise waiting for that. The advantage being that you can then make use of the acknowledgment and retry mechanism available in the LowPowerLabs implementation.

@Robert.Wall , @TrystanLea Thanks very much for your answers to my questions, which have cleared up my confusion :blush:

The future LowPowerLabs firmware for the emonTx3 and emonPi sounds good.

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Something else for the docs. Screen shot as an image. #pleaseaddtothedocs

The original is .svg - available if needed.

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For anyone interested in the radio formats, I have (rather belatedly) found the following documentation:


apologies I should have linked that in here sooner!

A follow on question (sorry!) - will the future LowPowerLabs firmware for the original emonPi include continuous monitoring (emonLibCM) or the original default Discrete Sampling library?

If I’m involved - whatever update is needed for the ‘old’ emonPi, it won’t happen for a while. I’m far too busy with the emonTx V4 and it’s likely to remain like that for the foreseeable future. You can always use the emonPiCM set of software, which is available for the entire “emon” range (emonTx V2, V3.2, V3.4 but excluding the emonTx V4 and the long-obsolete emonGLCD and NanodeRF), and uses the rfm69nTxLib for transmitting and the (patched) RF69 library in the emonPi for receiving.

Yes it’s my intention to use adapt Roberts emonPiCM firmware to use the LowPowerLabs format. The changes are relatively small and for now @Robert.Wall I don’t plan to add anything relating to this to your work load :slight_smile:

I’m a bit delayed on this work though @rupert as I’m trying a finish a couple of emonTx4 documentation related updates, I might have been optimistic on timelines…

Thanks @Robert.Wall, @TrystanLea for the updates. I can understand that you’re both very busy at the moment and don’t have time to work on the ‘old’ emonPi. I’m very grateful for all the current work that you’re both doing. I was just interested in what the plan for the future was.

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It is high up on my priority list, so hopefully sooner than later!

For information, I have tried, to the best of my knowledge, to put together a table of device vs radio format which may be of interest. My apologies in advance for any errors! The table is a snapshot in time, as things will probably change in the future.

I have included the Mk2 PV Router by @calypso_rae as it is a very popular device.

Any corrections or comments are welcome.

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Thanks Rupert that’s a useful table will help me make sure I tick them off!

If you could send the table to me in an editable format (anything is fine), I’ll create a docs page for it.


Can you include the RFM12 as well please?

Note 5 is not accurate, the Mk2 PV router (English version) has always been supplied with an RFM12B
But there’s no reason why it cannot adopt the ‘Native’ format with an RFM69CW if desired.

I can’t comment about the French version.

Well I can only say that my recent Mk2 PV router (English version) kit came with an RFM69CW …

What I meant in the table was that the Mk2 PV router kit needed to include the RF hardware option and that the appropriate firmware was used.

I don’t know if or when Robin changed from supplying the RFM12B to the RFM69CW. His parts list includes both the RFM12B and the RFM69CW.

I believe there are some discussions at The emonPiCM - #42 by alandpearson on RFM12B vs RFM69CW. I don’t know if this helps.

@borpin message sent

There is also some information on how to to simultaneously receive (and perhaps transmit?) two (or more?) 433MHz Radio Formats at once on an emonBase, using two (or more?) receivers/transmitters…

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Having looked, I wouldn’t call it “simultaneous”. There are two parallel receivers, not one receiver switching between formats or receiving either format and correctly recognising and decoding it. I know it’s moot, but it could be misleading without a careful explanation.