I am contemplating building a somewhat complex heating control system. I find lots of sites that will sell me a single board computer, but not a lot of information on what bits and pieces I might need to go with it, nor whether it can be mixed and matched with accessories from other suppliers.
And, on top of that, SBCs tend to be pricey - in fact the cheapest solution to to buy a slug (NSUl2), but then you have the problem that everything else has to come in the form of external USB-pluggable devices and you finish up with a bird's nest :-(.
What I need is:
SBC ARM-based with 32MB Ram, 16MB flash (or, better, room to add a memstick with just a bootloader in the onboard flash), ethernet connection, and some bus with a well-established interface.
Additional card for A/D converter(s)
Additional card for connection to push buttons, external relays, etc.
Additional card for LCD with maybe 100x100 pixels.
Possibly wifi card.
Possible battery backup.
Plus, of course, powersupply, enlosure, etc.
I have no problem with hacking the enclosure to take it all, and to provide bits of straightforward circuitry for sensors, pushbuttone, etc.
And I have head that the PFI bus might be sensible for the purpose.
But adding up all those cards from the sites that I have seen seems to be a bit pricey :-( .
Suggestions, preferably for stuff obtainable in the UK, or at least in Europe?