I am trying to get my daily bargraph running that shows how much energy is being sent to my car using an openevse. The charger reports properly to emoncms which I have running on ubuntu 20 on my proxmox server. I cannot figure out why the feeds are not calculating properly. I followed the instructions, but for some reason its not accurate. Why is it saying (247.35) on my last line of the feed processor? I just added line 3, to try and get that to 24.735 which was the last usage. It did not update when I added that.
I need to know the history to answer that. You wrote
[ × 0.1] but that’s in the input to the accumulator. If it had already accumulated 247, it will now go up at one tenth the rate it did before. I think you need to clear the feed and start accumulating again - that’s if I understand correctly what you are expecting.
So remove all the multipliers? How do I clear the feed?
I am trying to show my daily kwh usage from the watts drawn by my charger.
Do you understand how the Process List works?
I’m not sure what you are trying to do - I don’t know what the initial value is, you seem to be dividing by 10,000 where I’d expect to see 1000, and then you’re dividing by 10 again.
You clear the feed on the Feeds page - click the dustbin icon and it’s one of the options.
Exactly. I am trying to find some documentation on how these feed processors work. I am trying to capture the active watts which is not a time scaled unit. Its just the live wattage, convert that to kWhours and then have that reset daily in a graph so i can see what was consumed each day.
I’ll do my best, but I’m not an emonCMS expert.
So the input is the power in watts.
That enters the list at the top.
Normally, the process step modifies the value and passes it down the list to the next step. But there are exceptions.
Your first step, “×” multiplies by the fixed value you give it, and it passes the changed value to the next step.
If you choose it from the drop-down box, the only documentation there is appears in the blue text below. (Years ago, I suggested each process needed “comprehensive” documentation and the blue text was the result.)
Your next step, Power to kWh, is where the integration happens. It uses the feed’s interval setting and does the integration to produce kWh, with the ‘kilo’ multiplier built in. It writes the data into a Feed (i.e, the database), and as the last line says:
Output: Does NOT modify value passed onto next process step.
but passes the input power value (not the energy) down to the next process.
“Log to feed” is another exception that passes the input value on unchanged.
Some of the processes treat a large step towards zero as a fault (assuming that your emonTx or emonPi has lost power and the energy values it is sending have reset to zero) so instead, these automatically add the last feed value seen before the interruption, as a constant to the incoming value so that the energy accumulates uninterrupted. Wh Accumulator and kWh Accumulator are two that do this.
ok that helps a lot. Do you have a suggestion on how this should be setup to do what I would like?
I split the details of the processes into a new topic. Here’s what @Rolop wrote in answer to the original question:
Hello Jason,
Based on my experience if the original value coming into that input is in W then you would only need the power to kWh process to be able to create the daily kWh bar. The accumulator I think is only used for pulse meters.
To create my daily kWh graphs from my CT sensor readings I used the following process:
Which gives me the following bargraph:
Hope this helps!
Rocio