Emonpi monitoring 30 CTs (Raspberry pi and 2 arduino Megas via USB))

Hello all, I am new to the forum, and still very much trying to learn my way around Emonpi. I am wanting to attempt a custom setup consisting of a raspberry pi, usb connected to two arduino Mega2560s.

I have two main service panels side by side, with a with solar installation… I would like to measure the mains on both panes, the solar (back fed through a breaker into panel 1), and the rest of the breakers as well. I do not have a need to use the radio communication if I can send all the data via USB.

First of all, has this type of configuration been done and or and documented? If not, can someone help me to determine if this is an acceptable approach to monitoring or if there are other limitations I should consider before attempting.

Just for clarity, I do have a CT working on the arduino 2560 board and can see that it is measuring current from the raspberry pi via a python script I found on the emonbase image. (I would have to look to see what i used) I have not been able to get the inputs to register in emoncms. After much testing, and arguing with the emonbase installation, I figured I would ask the experts for the best approach to move forward. It appears everything is setup to use the radio communication, and I am having trouble understanding what I do and do not need to do if I do not use it. For example, is there a need for the firmware upload to the arduino?

Thanks for taking time to help me get pointed in the right direction and providing any help you may offer.

I assume that you have searched the “Archived” section, and found nothing?

That largely depends on what you’re trying to do and the processing power available to you. You don’t give any indication of how you measure the current and get the result to the RPi, and that’s probably the area where you’ll hit a bottleneck.

Using the default values that we use, a discrete sample takes 200 ms, to which a few more ms needs to be added for formatting and sending the value. We do that sample every 10 s. That sort of rate will be possible with 15 inputs, but you won’t be able to sample much more frequently than once every 4 s.

If you look at the emonTx sketches, you’ll find examples of serial communication - though not using USB as the emonTx does not have that.