Re: Software for Central Heating Control

[meow2222@xxxxxxxxx]

John Rumm wrote:
> meow2222@xxxxxxxxx wrote:

> > For the computer side of things, I would steer well clear of PCs, as
> > you need a system that will stay running for years at a time, and PCs
> > simply dont have the necessary hardware or software reliability. My
>
> I don't think that is true. Embedded PC hardware is designed for high
> availability applications and should run flawlessly for long periods.

Maybe you're right. But OP needs to bear in mind the system needs to
run reliably for at least 30 years, and servers are not designed to
that high a reliability level. You'd need to source that PC very
carefully. Or perhaps have a backup available with no need for extra
setup work.


> Remember also there is no reason you need to stick anything Microsoft on
> top of it - you can even program for the bare platform if you really want.
>
> So software reliability is down to you.

I took it as evident MS products would not feature in this one. Linux
is AFAIK not nearly stable enough to run for 30 years without
maintenance, or even 3. Perhaps there are PC OSes that are, and I just
dont know of them.


> > first choice would likely be a BBC B. If youre not familiar with them,
> > theyre 1982 32k 4MHz command line machines with inbuilt OS and BASIC,
> > and are stable as a rock. They also have lots of A./D I/O onboard, and
>
> Lots of them are failing now - just due to age alas. Many with PSU
> faults attributable to failing capacitors. I am not sure I would want to
> spec a modern design with a system that is no longer supported or
> available.

Todays PCs will be no longer supported or available when they go wrong,
so I'm not sure how much difference there. The 2 plusses with BBCs is
1. they have an ongoing niche market, making replacement easy and
minimal cost.
2. They need almost no setup: just plug the EPROM in and switch on.


> The IO they had was good at the time - but perhaps less use than might
> be expected in a modern context. Lack of TCP/IP, X10, Bluetooth, USB,
> WiFi stacks and interface logic may prove a bigger hurdle.

I guess so, had forgotten about the web interface requirement.


NT