Pi vs Tx for complete beginner

Hi all.
Can I have some opinions please.
I’d like to monitor my heat pump set up.
The Consumer Unit and main incoming supply is not conveniently placed near to the heat pump so I think I’ll just settle for putting a CT clamp on the Live cable for the heat pump and connect a temperature sensor each to the HP flow, HP return and outside.
I have zero knowledge of coding, apart from being able to get python to say “Hello world”.
I am thinking that the EmonPi will be the simplest solution as it has a display that might help a complete novice get to work. And it looks like the TX won’t be avaialble for some time due to semiconductor shortage.
I don’t mind paying a bit more to avoid frustration and several hours/days/weeks of trying to figure it out. But someone could convince me to spend less if they think someone like me could figure out the TX.
Does this sound sensible?

Welcome, David, to the OEM forum.

I’m afraid it’s not exactly an either/or – emonTx or emonPi. The problem with an emonTx is, what are you going to do with the data?

From what you’ve written, there are three choices:

  1. An emonTx plus Wi-Fi adapter, sending data to the on-line emoncms.org
  2. An emonTx plus Wi-Fi adapter, sending data to your own server running emonCMS.
  3. An emonPi running its own emonCMS.

The emonPi’s display is useful, but it doesn’t really help a great deal. It’s not intended for continuous use (the backlight times out, though that could be changed). Your main display will always be via a web browser.

We’re expecting the new emonTx V4 to be available later this summer. We don’t yet know the details of what it will finally have, nor a price.

The emonPi is actually a Raspberry Pi plus a cut-down (2 current inputs instead of 4) emonTx, plus the display, inside a box. Everything else is pretty much the same. You can (presently) do slightly more with your own emonCMS than you can with emoncms.org - I’m not sure whether that will affect you, given what I think you might be doing with the data.

I’m not sure I understand what your fears are, I hope this helps. Of course feel free to come back with more questions.

Thanks Robert. This is useful.
If it helps, what I’d like to be able to do is monitor the HP performance (the COP) in order to be able to make changes to the system if possible. I think I don’t have a particularly well designed system but I want to know how well it’s running now before I make any changes.

My fears are: I have very little time to research into how to make things work if it doesn’t work more or less out of the box. I have an 18 month old that I’d rather spend time with! Anything that I can do to reduce the risk of having to research areas that are very far from my comfort zone I am interested in.

I’m happy to wait till summer - it’s when the heating kicks in properly next winter I’m most interested in.

Thank you

That is a good start

That will work. Just take care with putting the CT Clamp on.

For the sensors, the shop sensors plus an expansion board will do that. Needs a bit of effort to ensure the sensors have a good contact with the pipe and insulate over the top.

EmonPi will do this job for you. You just need 2x 13A sockets handy. The emonTX is effectively the EmonPi without the Pi. The software for visualization runs on the Pi.

This will give you lots of graphs and there are a few folk here monitoring HeatPumps as well.

You mean a split-core current transformer. Current transformers with a ferrite core are VERY brittle, and there should be no means of fixing or clamping the c.t. to the cable other than the mechanism provided by the manufacturer, if any. Any mechanical stress on the core is liable to fracture it, destroying the c.t.

Sorry :sob: :bowing_man: