Multiple IoTaWatt How to combine the data

Hello all

I have connected two IoTaWatt units to my power panel, I did this because there is no way to monitor the main feeds to my power panel (Buss Bars cover with protective plastic) also there is no room to run wire backward through the CTs, So I am trying to monitor all of my loads to come up with a total power consumption all works great but I am having a problem in trying to figure a way to bring both units data together so I can come up with a total. I also have a Solar Feed which I plan on monitoring to determine if I am generating power to the utility or pulling power from the utility.

Sorry if I have posted this incorrectly

No There is no provision for individual IoTaWatt to combine their local datalogs. You would need to use one of the data upload services to send it to an external database.

I’m pretty sure you can do this with Emoncms, but I saw where they gave you short-shrift as is customary over there if you mention IoTaWatt. Their product line often results in multiple “nodes” reporting data that is combined. But you are now officially in the outcast group that cannot get answers to any questions because you have an IoTaWatt. I’m running into more and more folks that get their IoTaWatt running very quickly then run into a wall trying to understand Emoncms. Sad.

But moving on, I’d recommend you look into sending your data to an instance of influxDB. That is becoming very popular with IoTaWatt users and uploading is fully supported. You will need to establish an instance of influxDB, and one of several reporting and visualization packages available like grafana.

I’d prefer that some of the more knowledgeable users here on this forum take a few minutes to help you with this if you can’t find what you need on the internet.

Another approach might be to reduce the number of inputs that you need to 14. I don’t know how many circuits you have, but there are ways to combine multiple circuits into a single IoTaWatt input. You can pass multiple conductors through a single CT and/or combine multiple CTs together into one input using a simple commodity headphone splitter. I’m currently revamping the documentation site and will have a section on how to do that soon. With a single IoTaWatt, you can upload your generation and consumption to PVoutput, which is a simple, reliable and free service to handle PV output vs generation data.

There is also the possibility that you could get larger CTs that are designed to go on bussbars.

I’m quite saddened to hear of the issues @overeasy with the team at and your product. Both are doing an exceptional job with the technology to monitor systems, etc. It is so much easier when people get along.

@epirie, I today use the EmonCMS locally via a RaspberryPi and this would allow you to have multiple device reporting in to it and combine the inputs from multiple IoTaWatts if that is simply what you are looking to accomplish. The EMonCMS group have both the SD Card image and install instruction for deploying your own EmonCMS server which is rather inexpensive and you ca send it nearly as many feeds for no cost.

The downside is that with it being local to your network, you would need something like a VPN or other way to connect to the server when not home. I really like that I can use both EMonCMS and PVOutput (Thanks again Overeasy for this one), to collect total consumption/production and send this to PVOutput which is reachable anywhere. But, my multiple monitored circuits I have my CTs are safely only reachable on my local lan.

Below is a screen image of the dashboard I have for the various monitoring feeds, etc. A bad solar day today!

Thank you for the information i now have a direction to head, I will be spending time reading up on influx and how to send my data, I was thinking of buying an emonPi to use as a logger but do not know if it is worth it or would even do what i wanted.

Thank you for the info your dashboard looks great I have a long ways to go to get my system up to the level yours is running.

the emonpi runs EmonCMS and for your purposes has the same capabilities as I’d recommend that if you want to try to use EmonCMS, you first get it working on There is no initial investment, and you don’t need to learn how to administrate the system. If you find that it suits your needs, you can get an SD card from OEM and setup EmonCMS with a $35 Raspberry Pi that would be equal in function to what you would be running on With the IoTaWatt, there is no need to get an actual Emonpi with its two-channel energy monitor.

You could also add influxDB and grafana to the same Pi to try that out. I run both on a RPi with no problems.

@epirie I started to look at the EmonCMS from, but as of last year they started to charge a dollar per feed which is not much if you want to test and play with a few things. As you ramp up and start to build your own feeds around actual, min, max, daily, feeds add up quickly and I think I have upwards of 40+ feeds. Again not a bad price at $40.00 a year for someone hosting for you. However, as overeasy said below, a PRi can be had for in investment of $50-$70 with an SD card and you can have nearly unlimited feeds in your own system. Just a few thoughts

My dashboard has grown and changed over the months as I found somethings I was interested in and others I found less helpful. Remember is it is a journey, and a fun one at that! Enjoy the trip…