Emoncms with existing Pi running Apache2

I have an Arduino with current sensors communicating by radio with a Pi. Unfortunately the supplied SD card for the Pi appears to have corrupted sectors so I need to start again.

I already have a Pi 3 running as a web server. Presumably I can add the hardware radio module to this Pi and use it to run emoncms as well? What software do I need?


OK I have found
which explains this.

I have another question. I want to install the drivers for the RFM12Pi v 2.6 hardware module and test it on my Pi 3. I am looking at

but it seems as if all this is replaced by

I need to read this. Thanks for reading.

I would highly recommend starting with a pre built image to run emoncms on a RaspberryPi. Image can be downloaded here:

See emonSD forum category and follow user guide:

I would start here emoncms/readme.md at master · emoncms/emoncms · GitHub it gives you instructions for installing emoncms from scratch on an existing setup. I did this about 9 months ago and I only remember one issue (although I can’t remember what).

{edit} I installed the OS onto a HDD rather than to an SD card. The SD card errors are probably due to too many write cycles. The HDD was simply and old one out of an end of life laptop in a cheap case from Amazon. There is a script to move the OS to an HDD somewhere.

I would start here https://github.com/emoncms/emoncms/blob/master/docs/RaspberryPi/readme.md it gives you instructions for installing emoncms from scratch on an existing setup

Following the Raspberry Pi install guide will work fine if the file system is installed onto an external hard drive. However due to the disk write rate of a logging application such as emoncms I would not recommend using it with an sd card without the low write optimisations implemented on the pre built image. The guide the build the image with the low write changes can be found here:


The pre built image is based on standard raspbian with emoncms setup and optimised to work out of the box with zero setup and extensively tested for stability and reliability. Using the pre built image will allow us to offer better support as you will be starting from a known starting point.

It might be worth adding this as a line at the beginning of the Readme.md

Are there build notes detailing the changes made to the standard raspbian image? Many of the changes made are really good just for general raspbian images so would be good to document somewhere. I am presuming you have a build script you use?

I think there needs to be a recognition that not everyone wants to use a Pi just for Emoncms so constantly simply pushing that agenda can have a negative impact. Me, the pi that runs emoncms does a whole lot more as well, but I am really reluctant to upgrade from 9.2 as I suspect it will cause a whole load of angst.

1 Like

Totally agree, I don’t warm to this either…
A similar discouraging discussion has taken place on Github over the past few days



Paul / Brian - Me being a bit new to all of this - please help me understand. What do you use for emoncms? Or maybe that isn’t the issue. Sorry to be naive.

Sorry, don’t follow…

from this line here... It sounds like you don't use a Pi. Or does this mean the Pi is used for LOTS of thing plus some emon stuff.

Keep in mind my only experience with a Raspberry Pi is the emonPi. I had never used anything Pi-ish before.

EDIT: Never mind - I read thru the github link provided. Tnx!

Despite it’s size and cost, the Raspberry Pi is quite powerful, and emoncms hardly pushes it’s resources, so many users combine emoncms with other functionality. For example, my v2 RP runs;

  • Emoncms

  • A media server which stores & serves HD video to my TV & tablet, and my mp3 collection to my phone & audio system.

  • A fileserver which enables my laptop, tablet and phone to be securely backed up.

  • A webserver serving an extremely boring and incomplete blog.

As well as node-red and lots of other functions too.


Brian wrote (my bold)

which meant that he believes many people could and might use it for other things as well as, and at the same time as, using it for emonCMS.

got it! I read thru the github link and that helped! So this type of use would never use the image. Now the light finally came on (no energy related pun intended)

2 posts were split to a new topic: Can somebody please confirm that this image works in Pi’s 1,2 and 3?