EmonTx4 Documentation

Starting a new thread here so as not to overload the original EmonTx4 thread with documentation updates (See original thread AVR-DB: emonTx V4, new hardware in progress - #261 by TrystanLea).

The new emonTx4 documentation is available here: https://docs.openenergymonitor.org

We are in the process of moving from the old guide documentation to this new site based on ‘Read the docs’. This will house both the existing documentation e.g emonPi and emonTx v3 in addition to the new hardware. This new implementation builds directly from the documentation placed in e.g the emonTx4 GitHub repository itself, so you can choose to either view the same documentation on github or with the nice ‘Read the docs’ theme.


Latest updates:

  1. There is now a new section in the ‘Adding an emonTx4 to an existing install’ covering adding the required emonhub node decoder Adding an emonTx4 to an existing installation — OpenEnergyMonitor 0.0.1 documentation. There is also a new option mentioned called autoconf which can be enabled at the top of the emonhub config file. This automatically configures nodes based on a list of available node decoders. I will be adding more detail on that in the emonhub documentation section.

  2. There is a new page covering the new RFM69-SPI board the we are shipping with the emonBase New: emonBase with RFM69 SPI (Direct) — OpenEnergyMonitor 0.0.1 documentation . The RFM69 module is connected directly via SPI to the raspberry Pi. A LowPowerLabs format python library is installed by emonhub for use with the new RFM69LPL interfacer.

  3. There is a start on a page for the now legacy RFM69Pi adapter board. The page covers using the RFM69Pi adapter board with the emonTx4 including the option to either use the original JeeLib Classic radio format or update the firmware on the RFM69Pi board to a new firmware that supports the LowPowerLabs format.

  4. Mhz replaced with MHz in the few places I could find via a grep search, thanks @Robert.Wall :slight_smile:

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Looks great! Couple of bits :slight_smile:

The OEM icon is not appearing in the browser tab - perhaps do something so it is easy to distinguish the docs from the other OEM tabs I have open :rofl:

Couple of other bits (as I’m not sure

Perhaps amend this to say emonBase or emonPi Firmware — OpenEnergyMonitor 0.0.1 documentation

On Arduino instructions, as a new user, it took me an age to work out where the ‘libraries’ folder should go!

Please add to docs

The libraries folder is a folder that must be added to your Sketchbook folder (location found in preferences).
Simply create the folder named libraries in that folder and place the libraries you need, there.

Select Board - this needs to be added under ‘Compilation’

before the ‘select chip’ can be done.

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Thanks @borpin will incorporate these, much appreciated.

The “old” Installing Libraries documentation says (or used to say) this quite clearly - plus the reason for it.


Latest updates today:

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Documentation updates so far today:

There’s a lot more updating of the older documentation to do. We’re focusing on getting the new structure worked out and documentation moved across first, so please bear with us if some parts look a bit disjointed :slight_smile:

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Documentation states default wifi AP for setup is ‘emonpi’ and password emonpi2016. My TX4 just arrived (ordered release day), the AP is actually emonSD, after a few combination guesses I’ve found password is emonsd2022

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Thanks @Rincewind, fixed and improved a few other formatting related items.


There is now a new emonTx4 documentation page on using the temperature sensing, pulse counting and analog input (available either via the RJ45 socket or the pluggable terminal blocks. Please see:

emonTx4 documentation: Temperature, Pulse & Analog

The analog input documentation discusses how to use the analog input for use with a Sika VFS flow meter which has an analog voltage output.

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Thanks Trystan: very useful as always. Is it worth mentioning in this section that the default firmware does not automatically align the T1,T2,T3 outputs with the three ports? I’m presuming that the sensor ID could be hardcoded to a port as in the past. Fortunately, I did the “finger test” before attaching to the ASHP!

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Thanks Andy, that’s a good point. Will add that as a note.

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Direct installation: The emonVs can be hardwired by a suitably competent person into a 6A or lower circuit protection device in the fuse board (consumer unit) or a 3A fused spur. The supplied emonVs mains power cable has a cross sectional area of 1.5mm2. This can provide a tidy installation if no socket is available and helps ensure higher monitoring uptime if sockets are at risk of being unplugged for use by other appliances.

I think the cable was determined to be 1mm^2 in the EmonTX4 discussion? Just a note.

It would also be good to add in the docs what the default node is - it looks like its Node 17? And also what the individual feeds in the node are - I just get inputs 1-26.

Assuming Node 17 is the EmonTX4, I assume I can apply the profile in the feeds setting for EmonTX4 and it will name the inputs - be good to cover that in the docs for those adding to existing systems that do not recognise it by default.

EDIT: Sorry found it now under existing install config:

@TrystanLea did you get anywhere adding the GitHub source links?

Are the new CT directional? There is a marking


L is load? No mention in the documentation?

Yes that’s correct, L is in direction of the load

They are directional in the sense that when they are coupled with the emonVs voltage measurement, L to load will give you a +power reading whilst the opposite will give -reading.

On the house grid connection with exporting solar that would read negative power and positive when importing

Thanks, that’s what I assumed.

Further feedback: In the serial section:

It might be worth adding a note that if you cannot get a connection with the USB-C in either orientation, to try another cable in case the one your using is only wired for power.

Don’t ask how I know… :roll_eyes: (the Anker print should have been a clue!)

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