Archived Forum

Will using the "kwhtopower" processor after calculating your accumulating kwh do what you want?

Paul 

paul,

I haven't seen that processor but it sounds like it ought to help. I'll have a look and see what I can work out.

Thanks.

Paul,

Maybe the process you are referring to is Power to kWh. That is the opposite of what I want to do!

Andrew

https://github.com/emoncms/emoncms/blob/low-write/Modules/input/process_model.php#L282

Ah! Just checked something fuelled by your comment and found it didn't make it into the menu of the low-write v8.5, but it is present in the code as linked above so I don't know what's happening there, This has been spotted before see this Re: V8.6 - 9.x (extended) Development discussion.

Paul

Hi Paul. I take it that means I can't access this processor? Sorry but linking to reams of code isn't much help to this non-techy! I am just accessing the Emonpi in my browser, have nothing installed on my laptop and no server, wouldn't know how to update the Emonpi if I needed to without detailed instructions.

Andrew

It would seem that way, 

My link to one specific line was that was the the only place I could think of to confirm the existence of the kwhtopower and that it was included in the low-write version, it wasn't until I thought about it some more as to why you hadn't seen it that I recalled the other thread, hence the second link.

Sorry. I don't really know what would be needed to get it functioning, 

Paul

Thanks Paul. Do you know of anyone I could ask?

I wish I could help, but unfortunately not :-{

Paul

Hi,

Does your sketch send the number of pulses seen since the last sent ?

Does your sketch send data at a fixed and stable rate ?

If YES and YES, you can approximate the power without the kWh to power process.

Just apply a scaling factor to the number of pulses seen since the last sent.

Example with a meter with 1 pulse = 1Wh .  If you got 4 pulses since the last sent and if you send data every minute, the approximate power is Power = Energy/time = 4Wh / (1/60h) = 240 W.   Here the scaling factor is 60.

Eric

Hi Eric,

Thanks for your reply.

Unfortunately as I have explained earlier in this thread I am programming-illiterate. I don't know what a sketch is. In fact I probably don't have one. I am using an Emonpi as supplied with no alterations to the image (I hope that's the right term) or configuration settings.

Andrew

Ok,

I just looked at the emonpi sketch.

It doesn't send the number of pulses since the last sent. It only sends the total pulses since boot.You may get the number of pulses since the last sent using the "Total pulse count to pulse increment" process. This process is available on some emoncms versions.

Is this process available on your EmonPi ? (check on the web interface)

The processes I have available are

Log to feed

Wh Accumulator

Power to kWh

Accumulator

Then calibration + -

Then input +-/x

Reset to zero

Allow positive

Allow negative

Unfortunately, I see no other solution than modifying the sketch.

Otherwise, you can send your data on emoncms.org where the "Kwh to power" is available but you will start from scratch...

Sorry Eric could you please explain in more detail your comment about starting from scratch?

Hi,

If you make your RasperryPi send your data to emoncms.org, you will have to re-configure everything again ... input/feed/vis/dashboard.

Eric

Hi Eric,

Thanks, In my ignorance I didn't realise there was a difference between what I have been doing to access the data (navigating my browser to emonpi/emoncms) and doing it via www.emoncms.org as you describe. I thought I had been uploading data to the web site whereas it seems I have only been accessing data stored on the emonpi!

Could you please point me in the direction of a guide on how to configure my emonpi to upload data to emoncms.org?

Andrew

Hi,

Create an account on emoncms.org.

Log in and go to your account setting page (http://emoncms.org/user/view) to get your write API Key.

Then follow that.

Eric

Hi Eric and thanks for you perseverance. I have tried what you suggested but have hit a brick wall as no nodes appear in my emoncms.org account. I assume I have to alter the configuration of the emonpi?

Andrew

You do indeed. See section 4 - Logging Data Remotely in the emonPi setup guide.

Cheers Robert. I seem to have missed all this when I was setting up, perhaps because there was so much information I didn't know which bit I needed ;-)

Update - I seem to be going round in circles again, that's the same link I followed from Eric's post and it didn't explain how to configure the Emonpi

Hi,

I have no Emonpi with me but I do not understand why do you say this page doesn't explain how to configure the emonpi in order to send data to emoncms.org. Everything is clearly explained. Maybe not as detailed as expected but it does the job.

Copy paste from that page :

As well as logging data to the local Emoncms installation, data can also be logged to a remote Emoncms server such as emoncms.org.

Assuming your still logged into Emoncms locally on the emonPi, select the EmonHub tab. Here we can edit the emonhub.conf configuration text file.

To enable remote logging, you will need the Write API Key of the Emoncms account you intend to post to. Paste this API key into the emonhub.conf file overwriting 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' at the bottom of the the Interfacers section then hit Save.

As mentioned in my previous post, the only thing which is not clearly written is that you have to create an account on emoncms.org first to get you apikey.

EDIT : you will not see appear your nodes in my emoncms.org as in Emonpi. Your data should appear in "Input".

Let us know,

Eric

Eric,

I think my confusion stemmed from trying to follow other instructions I'd found here on editing the conf file using something called putty, which I tried and failed to do.

The good news is that thanks to your help, and that of others in the Questions and Support thread, I now have my emoncms.org account up and running with data from my Emonpi.

I have used the kWh to power process but I would be interested fo know what calculations it carries out? I used the default settings.