[Embedlets-developer] Elevator Challenge update

[Ted K. <tk...@ya...>]

The Elevator Challenge has turned out to be an excellent
application for discovering how Embedlets might work in
practice.  Also, solving this challenge using a visual
mockup of what the Graphical Wiring Tool might look like
was definitely a good strategy.

So far the 6 interfaces I started with have been reduced to
the following 2:

SignalSender and SignalReceiver

and all signal customization is handled through subclasses
of a main SignalEvent class.


The solution has also become distributed across a main
controller Embedlet Container (located in a machine room),
an Embedlet Container on each floor and an Embedlet
Container in each elevator (I actually expanded the scope
of the challenge to accommodate multiple elevator shafts).

So far the main keys that have enabled a solution to move
forward are the following:

1) Limit all inter Embedlet/Peripheral/Proxy communications
to using the SignalSender and SignalReceiver interfaces.

2) Encapsulating all elevator logic in one Elevator Logic
Embedlet that can be visually configured for the number of
floors and the number of shafts it must accommodate.  After
one makes the assumption that a single Embedlet contains
all the logic needed to accommodate up to an 100 floor
building with up to 10 elevator shafts then how this logic
is implemented is no longer a concern (although there is a
good chance that it is internally implemented in Java).

As soon as the system's main logic was encapsulated inside
of one Component then the primary work involved with
creating a solution shifted to graphically wiring all of
the system's I/O signals into the Elevator Logic Embedlet.

3) Enabling communications between remote Embedlet
containers.  This had the effect of taking the fairly nasty
problem of figuring out how to route the signals from 10
floors and 2 elevators into the main controller.  Building
remote Embedlet Container communications into the mockup
allowed the solution for 1 floor's communications to be
enumerated across the other 9 floors almost effortlessly.



Finally,  these are my impressions so far of graphically
wiring together an embedded system using Embedlets:

1) It looks like it is going to work.  We should be able to
judge this better a few days from now, though, so lets not
get our hopes up.

2) It 'feels' like it might be an order of magnitude more
productive (no kidding) than current embedded technologies.
 I think that this means that embedded solutions could be
developed in an order of magnitude less time or that an
order of magnitude larger system could be developed in the
same time.  

If the following were true:

a) prebuilt software components were available that
encapsulated the 'heavy lifting' logic parts of the
application, like the Elevator Logic Embedlet (which is one
of the primary reasons for software Components in the first
place).

b) 100% plug-and-play sensor and actuator modules were
available to handle all of the system's I/O needs.  These
modules would need to automatically appear in the graphic
wiring tool as soon as they were snapped into the system.

c) we were using Embedlet Container 1.0 level software
which already had all of the needed interfaces worked out
in a satisfactory way.

then it appears that this application could be completely
bench assembled and tested (including both software and
hardware) within 3 to 8 hours.


3)  A non programmer who understood electronic interfaces
and the Elevator problem domain should be able to wire a
solution to this problem together.


Ted

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