OpenEnergyMonitor Community

Old hardware on modern Emoncms installation

Hi, I have an EmonTx v3 433Mhz sending dat to a RPi “Powered by | v8.1.2 (from apt)” and a RFM69Pi 433Mhz Raspberry Pi Base Station Receiver Board. I also have a emonGLCD monitoring my energy usage.

I wish to install a modern version of Emoncms version to bring myself into the 21st century and have a future upgrade path.

Is this hardware compatible with Emoncms without modification?

Thanks for any help.

Welcome back, Gary.

The short answer is, almost certainly, yes.

The long answer: Nothing much has changed regarding the way in which everything works in providing the data to emonCMS, so your Tx still sends its radio data packet to the RFM69Pi, and the RFM69Pi still sends the serial data via the header pins to the RPi. At the same time, the emonGLCD picks up the radio transmission and displays it.

I have an emonTx V2, V3.2 & V3.4 and GLCD, all working on the old 868 MHz radio and they all work with the latest emonCMS.

The only change is likely to be in the data format that emonCMS expects from your emonTx - the modern sketch sends rather more and so that might mean that you need, before you upgrade emonCMS, to take a copy of your emonhub.conf so that you can replace the new node definition for your emonTx’s NodeID with your old one.

Recovering your historic data is likely to be a problem - but my knowledge in that area is all but non-existent, so somebody else will need to advise you on that.

In any case, I’d advise starting with a new SD card.

Thanks for you prompt reply Robert. You have been a great help with these topics in the past.
I will need to update my knowledge of all this before I embark on this project. It’s been so long I will need to relearn so much.
As far as the historical data goes I have already resigned myself to not being able to transfer as I tried a few years ago and was unsuccessful. All data has been sent to PVOutput since the beginning so, although not as granular as emoncms data, I have this data available.
Wish me luck!

It’s still worth waiting to see if somebody who knows about transferring the data chips in. The format and location have changed recently, scripts have been written, so just because you failed then doesn’t mean all is lost now. If you keep the old SD card, you can always put it in another RPi and get at the data that way.

Yes I will do that. It’s on a really old RPi 2B from memory so can just shove it in “the drawer” for safe keeping. BTW transferred to a USB hard drive years ago which is possibly the reason for the longevity.
Thanks again for your help.

Revisions to how emonCMS writes to the SD card mean that we no longer use the “low-write” mechanism, how it might affect you if you continue with the hard drive I can’t say - it’s not an area I know very much about.

The RPi 2B isn’t a problem per se, but it can be slow making a really big graph.