Web framework for embedded system

[Thomas Heller]

I'm looking for a lightweight web-framework for an embedded system.
The system is running a realtime linux-variant on a 200 MHz ARM
processor, Python reports a performance of around 500 pystones.

The web application will not be too fancy, no databases involved
for example, but it will need to control some simple peripherals
(some parallel in/out, some dacs) attached to the system.

It should provide a user interface showing the current state and
allowing to manipulate it via a browser, and I will probably need
to support some rpc as well.

Does this sound sensible at all? Any suggestions?

Thomas

 

[Gerhard Häring]

I'm looking for a lightweight web-framework for an embedded system.
The system is running a realtime linux-variant on a 200 MHz ARM
processor, Python reports a performance of around 500 pystones.

The web application will not be too fancy, no databases involved
for example, but it will need to control some simple peripherals
(some parallel in/out, some dacs) attached to the system.

It should provide a user interface showing the current state and
allowing to manipulate it via a browser, and I will probably need
to support some rpc as well.

Does this sound sensible at all? Any suggestions?

I'd try first what I know best. In my case Django. Despite the
restricted hardware, it might just work fine because you'll only use a
tiny fraction of it.

If this doesn't work because of CPU or memory requirements, I'd next try
to build my own using components like

- CherryPy for the web server, it should also be able to handle your
(XML)RPC requirements
- some templating language like Mako (my favourite)

It doesn't sound like you need much more.

You could even build upon wsgiref, string.Template and the XMLRPC stuff
in the standard library, but that's for people who like tinkering ;-)

-- Gerhard

 

[bobicanprogram]

I'm looking for a lightweight web-framework for an embedded system.
The system is running a realtime linux-variant on a 200 MHz ARM
processor, Python reports a performance of around 500 pystones.

The web application will not be too fancy, no databases involved
for example, but it will need to control some simple peripherals
(some parallel in/out, some dacs) attached to the system.

It should provide a user interface showing the current state and
allowing to manipulate it via a browser, and I will probably need
to support some rpc as well.

Does this sound sensible at all? Any suggestions?

Thomas

You should definitely check out the SIMPL toolkit (http://
www.icanprogram.com/simpl). We have used this ultra lightweight
toolkit in several embedded Linux projects. It will allow you to
seamlessly connect your Python bits with bits more appropriately
written in other languages like C.

There is a "hello world" level tutorial on the Python-SIMPL
capabilities (which includes a web CGI interface) at:

http://www.icanprogram.com/06py/main.html

If you have any questions about our SIMPL experiences don't hesitate
to ask.

bob

 

[Suraj Barkale]

I'm looking for a lightweight web-framework for an embedded system.
The system is running a realtime linux-variant on a 200 MHz ARM
processor, Python reports a performance of around 500 pystones.

You can start with webpy (http://webpy.org/) and build up from there.

The web application will not be too fancy, no databases involved
for example, but it will need to control some simple peripherals
(some parallel in/out, some dacs) attached to the system.

It should provide a user interface showing the current state and
allowing to manipulate it via a browser, and I will probably need
to support some rpc as well.

Does this sound sensible at all? Any suggestions?

I don't know how Python will affect the real-time tasks your system is
performing. You may want to look at a web framework in C (e.g.
http://www.koanlogic.com/klone/index.html).
Regards,
Suraj

 

[alex23]

I'm looking for a lightweight web-framework for an embedded system.
[...]
Does this sound sensible at all? Any suggestions?

I'd highly recommend taking a look at CherryPy: http://www.cherrypy.org/

The developers describe it as a "HTTP framework", being lower-level
than most of the available web frameworks. But it should be very
straightforward and more than suitable for your needs.

 

[Thomas Heller]

I'm looking for a lightweight web-framework for an embedded system.
The system is running a realtime linux-variant on a 200 MHz ARM
processor, Python reports a performance of around 500 pystones.

The web application will not be too fancy, no databases involved
for example, but it will need to control some simple peripherals
(some parallel in/out, some dacs) attached to the system.

It should provide a user interface showing the current state and
allowing to manipulate it via a browser, and I will probably need
to support some rpc as well.

Thanks for all the replies I got.

I will take the 'traditional' route, and probably go with cherrypy first,
but will still keep an eye on webpy.

I'm very happy to see that these frameworks deliver ~10 pages per second
(cherrypy) or ~3.5 pages per second (webpy) out of the box on a system
that is 50 times slower than a typical desktop PC. Of course these
were very short pages.


The other ideas that were posted, the SIMPL toolkit and the
'Batteries Included! Python on Low Cost Tiny Embedded Wireless Devices'
stuff, are very interesting as well, but not for this project. Food for
thought, at least.


Thanks again,
Thomas