Way to add an initial meter value to start off on Emoncms

Is there a way I can input a value to a feed as the initial value from my consumption meters, before the inputs from emonTX start feeding it with constant updates?


What are you using to do the calculations? Also how are you monitoring the meters?

When I did this some years back on my test rig with an arduino, I just had a pulse counter and this accepted a string over serial for the initial value.

You could hard code it in and update the eeprom of the chip, but it does only have a finite life.

Now I am looking to do this in production now, I have a few other ideas, but if you advise what you use at the moment we can help get something going. Even if it’s just an API call.


I am feeding a pretty standard emontx power value as input into emoncms. Which is then collected in a Power to kwh feed. But this feed will have started accumulation from the time I started running my emontx. What I want to do is update that Power to kwh feed with what my meters are showing now on the displays. This will hopefully then keep all future updates to the feed in step with the actual meter readings rather than me doing the maths mentally!

It is possible to use the input or feed api to set the feed in question to a specific value, the trouble you may encounter is getting the timing right as a fixed interval feed will only update after the interval has passed so if setting a feed value on a live sytem it could get overwritten by an incoming value before it is saved.

It can be done but I would recommend creating a test feed to practice adjusting before doing your live feed.

Using the virtualization ‘editrealtime’ you can zoom in to the latest data of a feed. Zoom to the point you can reliably click on the last point, this will get the time and value for the point into the edit area, add 10 to the time and the value you want to change to and save. Add 10 to the time and save again. Refresh and check the last point is now as you want. (I am on emoncms.org with 10 second feeds).

Apologies if this is a bit basic, but for a one off change it works.

Try it on a test feed.

Have fun.