Build me a path from cradle to grave

[Richard Owen]

A confession: I did my degree in Computer Science. I went to work for a semi-conductor manufacturer and spent gainful hours designing and building microcomputer based systems.

It was a long time ago. I've now got my PV system in and my little hydro scheme (which needs some TLC to get it working again.) and I'd like to start by monitoring my generation and consumption and move on to controlling some loads to optimise both.

I was quite taken with EricW's monitoring system and I did have a quick look at the picaxe website but I didn't get very far with it.

So, for me and anyone else out there who thinks they might want to dabble in the same waters, could someone lay out, very simply, what it is I'd need to buy?

I'd rather buy a system powerful enough to do both monitoring and control even though I only want to do monitoring initially simply because I don't want to buy twice. Unless, that is, someone can point out a good reason for doing so.

Thank you.

[Andygodber]

Cost no object?

A confession: I did my degree in Computer Science. I went to work for a semi-conductor manufacturer and spent gainful hours designing and building microcomputer based systems.

It was a long time ago. I've now got my PV system in and my little hydro scheme (which needs some TLC to get it working again.) and I'd like to start by monitoring my generation and consumption and move on to controlling some loads to optimise both.

I was quite taken with EricW's monitoring system and I did have a quick look at the picaxe website but I didn't get very far with it.

So, for me and anyone else out there who thinks they might want to dabble in the same waters, could someone lay out, very simply, what it is I'd need to buy?

I'd rather buy a system powerful enough to do both monitoring and control even though I only want to do monitoring initially simply because I don't want to buy twice. Unless, that is, someone can point out a good reason for doing so.

Thank you.

[Baz]

I think if you want anything complex than logging or a fancy timer both of which fit the Arduino bill then you are looking at a mini ITX to give processing power with low power consumption.
Arduino has a high I/O to processing power ratio, sheevaplug etc have the opposite.
You might enjoy slaving a few distributed Arduinos to a main controller but risk never actually getting it working.
A headless Linux box would do the job but lose some of the user friendly attributes such as feeding the GUI to the TV for monitoring your PV output during advert breaks.
Mini ITXs come in around 12w I think (never done one) but add in the modem, router and i/o interfaces. As you will want some kind of UPS it would be better to start off straight away with a 12v or 24v battery psu rather than the mains psu.
Somewhere on the forum I think there is a calculation for PV array & battery size to greenify it all.
Have a look at 'Misterhouse' for the master app as it is in windows and linux flavours.

[Richard Owen]

Is there not something I could do with the Picaxe system? Or some other programmable chip based system? Or is what I'm looking at too complex for that?

I didn't really want to go down the computer based system approach precisely because I'd then need a computer and UPS (which I happen to have but didn't want to use for that.) I was hoping to have something I could programme and forget about (until I wanted to fiddle with it again, of course.)

[derekmt]

Is there not something I could do with the Picaxe system? Or some other programmable chip based system? Or is what I'm looking at too complex for that?

I didn't really want to go down the computer based system approach precisely because I'd then need a computer and UPS (which I happen to have but didn't want to use for that.) I was hoping to have something I could programme and forget about (until I wanted to fiddle with it again, of course.)

My approach is going to PC  with i2c  interface (reduced speed active pullups)  to start, to establish the the control algortihms needed. Then migrate the RT control to a PIC system but still have the PC as UI. Then migrate the UI to Android. But I'm doing thermal  with about 20+ heat measurement points 4 pumps 6+ valves etc etc...

My background is simliar Physics, microelectronics, silicon glen (motorola, fairchild, inmos) then telecoms.

[Baz]

Ah, a Picaxe is great for really simple quick cheap things like a basic timed heating controller for a couple of zones. But if you want a little more complexity like a display and logging you would need an Arduino. There is a design on the forum about a year ago for a multiple temperature logger based on the Arduino which would adapt easily to votage logging or you could make it work as a webserver to read the voltage remotely. However both logging and webserving might be just too far for one Arduino.
If like most people you are almost permanently attached to a computer you might be able to run a background task on your laptop that nips out and logs voltages across the web from a web connected Arduino. It would only have to store a couple of hours of readings in between. It might be able to email you the data too but increasingly ISPs are using secure authentication on the mail servers which is a step too complex.

[Richard Owen]

Ok. Let's, for now, say I'm going to use an Arduino based system.

What is the minimum I'd need to buy to measure the PV, and hydro production and the house consumption?

With enough headroom to do things like:

*) Switch off the hydro if it's consuming rather than generating
*) Switch in a variety of loads to minimise export

Thanks.