SWH project part 10 - temperature logging 2

Like I said yesterday, in the quiet patches between the bulk of the project making any headway, some progress has been made on my temperature monitoring system.  It all works happily enough on the desk; the next step is to get all the sensors mounted and wired up in a waterproof way and see if it still behaves out in the wet muddy real world.

Green and happy.
(no sensors plugged in just now, so values are nonsense.)

Nice and ordered in theory...

...a little more disorderly in real life.

Turning a 2D layout into a 3D structure and mounting it all in a tapering
cylindrical tub is an interesting challenge.

The multiplexer board will be mounted out at the panel site (in another
plastic tub), gathering together the inputs from 16 temperature sensors.
This means I only need 2 bits of wire 40m long instead of 16.

When panel overheat, SolarBot angry is!
He may even have a tantrum of irritating beeping noises until someone
does something about it.

SWH prototype project part 5 - temperature logging

A quick foray into some electronics, just for a change. The plan is to build a little data logger which will record the temperatures at various points in the panels and tank over the course of the day (or week, or month for that matter) - and thus save me having to take the lid off the tank and check a glass thermometer every hour!

This nifty little screen will eventually give an up-to-the-minute temperature display.



















For my fellow geeks, the red board is a Seeeduino Stalker microcontroller - an Arduino variant with onboard real-time clock and microSD slot for data logging purposes. I'll be connecting up a few MCP9700A thermistors in the next couple of days. In it's current state I have 6 inputs to play with - possibly expandable with a multiplexer at some later stage if I feel like it.

Time and part-availability* permitting I might think about adding a light sensor of some sort, and an alarm for if/when the panels get too hot in summer (so that someone can take some sort of action - probably just shading the panels. It'd be sweet to have some sort of canopy unfurl automatically, but I think that's probably a bit over-ambitious!)

(*a big problem - trade embargoes at the UK end mean RS orders take 6-8 weeks to arrive, after they've obtained an export certificate - I had to get our recent visitors to bring out the thermistors for me. On the other hand, the circuit boards arrived from Singapore without too much hassle...)



















The absence of breadboards means a whole lot of trying to solder ends of wires to each other - a bit messier than I'd like.

I think this soldering iron is designed for somewhat larger applications...