OpenEnergyMonitor Community

emonSD-24Jul20 release

Updated: The latest emonSD image build is now ready.

This image replaces the emonSD-17Oct19 SD card image. This new image includes the latest Raspberry Pi OS and all the latest version of the OpenEnergyMonitor and Emoncms packages, including use of python3 throughout (thanks to @bwduncan, @alexandrecuer and @borpin).

The image was built using the EmonScripts automated image build script:

Base image: Raspberry Pi OS (32-bit) Lite 2020-05-27

Image download: (Beta)

(.img) MD5: 1db713787a1f3469fc3a1027767fd607
(.zip) MD5: a160f746595872d30b735ab17e8a0b1c

The image is also available from the image download page here:

Updating emonSD-17Oct19: Application updates for this image are still supported via the emoncms admin interface. These updates do not include distribution level upgrades, for the latest Raspberry Pi OS please update by using the new image. See

NOTE: Updates are no longer available for the following images

With recent changes to use python3 throughout, the old update scripts used by the following images no longer work and so update support for these images via the Emoncms Admin interface has been disabled:


If you try and update and you get the following error:

ERROR: emonSD base image old or undefined…update will not continue

This indicates that you have one of the older images. We recommend upgrading via the new SD card method described here, it’s possible to migrate your existing data onto the new image as part of the process:



happy to test but what is the best way to do this, is it best to put it on a new card?
Is it possible to save the current data and then re-load to the new version?
Not a clue so simple instructions would help :slight_smile:


Have you fixed the processor speed issue for anyone using an older Raspberry Pi?

If not, you need to add a note about what needs changing.

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Yes, We have removed the modifications that were originally made, the settings are now the default settings that come with the RaspberryPi OS. As far as Im aware this should now sort the issue.


Hello @JJC, yes the easiest way to test / migrate is to write the new image to a new SD card and then import your existing data using the Import from USB drive method, see:

This approach does not change your original SD card and so you can always restore to your previous system by putting the old card back into the Pi.



All updated and running, found one thing though, ethernet works much better when connected to the correct port and not the temp port :face_with_symbols_over_mouth:
What feedback/testing do you want?


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You’re not the first to discover that. Reading the labels helps. Does the temperature/pulse still work though?


Yes fortunately all working :slight_smile:


Thanks @JJC great to hear! Just let us know if you notice any fundamental issues. @glyn.hudson and I are both running the image here as well, all seems to be working fine so far.

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This image does not have the comment that emonSD-17Oct19 did:

To use this image on Pi2 remove the following lines…

Can you confirm that this image does not support Raspberry Pi 2?

I am just starting out with OpenEnergyMonitor and have ordered an emonTx but hoped to convert my existing Raspberry Pi 2 into an emonBase (I also ordered the RFM69Pi to enable comms with the emonTx).

At this point it looks to me like I need to use the emonSD-17Oct19 image.

Thanks for your help!

Welcome, Michael, to the OEM forum.

It’s my understanding (see Avoiding wireless connections) that the specific lines you once needed to remove have been removed, so it uses the default for the Pi model in question, and there isn’t a problem.

I’m using that image on a Pi 2B.

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The emonSD-24Jul20 will work fine on the Pi2 without any modifications.

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emonSD-24Jul20 is now the main release! New units bought from our shop are now shipping using this image. I’ve updated the first post above to reflect the release status and a note on updating and upgrading older images.

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All units shipped from Tuesday 1st September 2020 will be running the new (emonSD-24Jul20) image

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I am a beginner with the EmonPi system. But I do read a lot about SD card failures and software tweaks that are used on the Emonpi to extend to life of the cards.

Would it be possible in the future to make available a tutorial and a dedicated image if it is required for installation on a USB SSD. This will in most cases completely eliminate the card failure problem. USB adaptor leads and SSD`s are relatively cheap so I’m sure this would be a popular option. I’m looking to have a system that will reliably gather data, operate demandshaper and as far as possible be fit and forget. The SSD option will go a long way to achieving this.



While it might be useful to have that all in one place, there are many guides already available on the Internet that tell you how to boot your Raspberry Pi from a USB drive. Once you have your Pi booting from a USB drive, use the build script already available to install EmonCMS. The same script is used to build the EmonSD image. Details are in the first post above

Thanks both for your anwswers.

I know of the different guides for SSD setup that are available. I just thought there may be some other considerations with the way EconCMS does things.

I have ordered a cable and SSD. When it arrives I will give it a go.

Many Thanks


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Loaded a fresh card with the latest release - smooth install/setup and all running from a backup. Good work all. :slightly_smiling_face:



I’ve been running the Oct 2019 image and updating it regularly. It eventually got to ver 10.2.6.

I’ve now downloaded the July 2020 image on a different SDHC and updated it (which seemed to change nothing) and it is showing the same ver 10.2.6.

I can’t reconcile this with the statement that Oct 2019 updates do not include distribution level upgrades, for the latest Raspberry Pi OS

What have I done wrong/misunderstood? Is the July 2020 image identical to the Oct 2019 image updated to today?

If that is the case, can I just stick with continuing to update the Oct 2019 image on my other running instances and avoid the export/import data hassle?

Will the Oct 2019 image continue to receive updates beyond 10.2.6?

Pls advise