[ha] Re: Basics

Vermeulen Nic (Nic.Vermeulen.at.mapp.rma.ac.be)
Mon, 19 Oct 1998 13:23:47 +0200

Hello All,

After this first week the HA list exists, I already have learned several
things: we have a group of very enthusiastic people here and I have to
read my mail sooner.

To comment some replies, I'm surprised that we are so much on the same
frequency,Robin seems like a great moderator.
Yes it is possible to implement a great amount of code without having
access to an eprom burner. When you use, for example, the mentioned
HC11, you can switch it in download mode. After the reset, the HC11 will
poll his serial port and store everything in his memory (EEPROM). You
can download a small piece of code (I believe 256 bytes) to blow a flash
eprom. After a second reset, you can download your actual code. You have
to take care a bit, but it is very cheap and user friendly. I imagine
this wrinkle must be possible on other CPU's also.
The basic based stamp: As I know it, the stamp has very limited I/O and
memory capabilities and the embedded basic is too slow for useful
control applications. Maybe it can fit somewhere, but I wouldn't
recommend it for the 'main controller'.

Safety: In every electronics magazine, there usually is a page about
safety rules. Maybe we can put a copy on the website.

Though I have no detailed idea of the necessary network, I don't think
we should stick to a single one. Flexibility also implies that you can
adopt new standards (easily). What I had mind was a powerful network for
connecting the more intelligent modules, but for simple light switches
and appliances, X10 has a very wide base of existing modules (herewith
covering the safety issue a bit). If in a couple of years one bus
becomes a standard, it should be possible to switch or add this bus.
I particularised 'no proprietary' in the initial specs, because I would
like to see the protocol published on the site, so one can change it
according the necessities. This doesn't mean that you cannot use a
commercial protocol. As I can see from here, Lonworks has released it's
Lontalk protocol for use on any processor, but I'm not sure you can
freely distribute it. Again, this should not be the only protocol, and
not the only available network.
I noticed we have a insider aboard (Welcome Rich). If (I said IF) Lucent
release their specs, we can all benefit from them.

I also noticed that there is some misconception about what this 'beast'
must do. Controlling lightning/ appliances/ security/ heating is already
a though nut but this appears to be a unity. I think it would be logical
to control these from one CPU. But maybe, I see this wrong?

>The house hub should be adaptable to any type of source,
>including carrier-current (X-10) or direct low-voltage wiring. This
>therefore presupposes an interface module. Do we say that the
>house hub accepts a certain type of input as a default and if you
>are using another transmission protocol, you add a different kind of