Re: [TF-AP] Follow-up to today's call

> On 30 Apr 2015, at 13:55, Hund, Johannes <johannes.hund@siemens.com> wrote:
> 
> Dear Task force,
> 
> following up on today's call I want to circulate the contributed sketches of the Architecture as well as the Protocol & API-sketch.

My regrets for today’s call, I have been travelling on work and unable to call in.  

For my part, I really have a very simple architecture in mind.  This is holding up well with the implementation work I am doing in odd moments of free time. The essence is the relationship between a thing and another thing that acts as its proxy.  Things are normally hosted by servers, but may be hosted by web pages.  To connect the web page to the server, I am using HTTP to download the thing description from the server, and a shared WebSocket connection for the messages between the proxy and the proxied things. Web page scripts are restricted by the same origin security policy. This means that the web page can only proxy or depend upon things on a server with the same “origin” as the HTTP server the web page was loaded from.  This restriction doesn’t apply to servers which are free to communicate with whichever other servers they choose to.

When it comes to interfacing to sensors, I have been looking at Bluetooth medical sensors where there is a logical domain data model coupled with a communication model.  For actuators, I have been looking at servos as used in robot arms and robot vehicles.  The servos are driven from microcontrollers like the Arduino which in turn are controlled by a more powerful device like a Raspberry Pi. For easy of prototyping, node.js is particularly good due to the wide range of open source modules available.  This allows for the development of different kinds of things as appropriate to the different kinds of sensors and actuators.

—
   Dave Raggett <dsr@w3.org <mailto:dsr@w3.org>>