XMPPHWFS
Under the barbarian name of XMPPHWFS stands the following idea:
hardware IOs made available (on a fuse filesystem) through xmpp messaging protocol. The latest idea is to use fuse only as on option, so the name will definitely change. locmon2 seems like a good candidate to me.
Contents
Description
XMPPHWFS is meant to replace locmon, which in my opinion was a good idea but is too buggy and impractical. from a recent copy of 20 minutes, it seems the industry is also heading towards something alike, only for home robots and social networking. WTF, tell me why your vacuum cleaner should tell all your facebook friends there's a plant in its way. Any suggestions are welcome, coding has not really started yet anyway.
- Debugging new hardware is simply done through communication with a human client.
- corecode suggest to use the PubSub mechanism for event notification, I think he's bloody right on this. Some bot can catch these events and update the cache DB as well.
- GUI can be implemented as a bot (ctrl_bot?). Simple and clean. Use of a cache DB is a good idea to minimize traffic and load on HALs. For the interface, I'd suggest HTML with Ajax with templates and possibility to include content like webcams and the such. Help is needed here.
- some other bot (log_bot?) can generate MRTG graphs and update the cache database on the same occasion. MRTG config can of course be generated automatically and graphs included in the GUI.
- The Fuse inteface, if needed, should also be implemented as a bot. Simply specify where to mount the filesystem, connect your bot, you're done. No need to have a modified jabberd and the resulting filesystem can be mounted on any host. Any interface of this type (read: local interface, as opposed to html-based) should not talk directly to HALs, but communicate with a bot (ctrl_bot?) that has access to the cache database.
- in case you really want to notify your friends through twitter, facebook or whatever else, create a bot and make it subscribe to particular events
it was suggested to use IRC for communication, but device description is be greatly improved through use of XML and XMPP is just that. AFAIK, IRC does not have a PubSub mechanism.
- I've been dreaming of a 3D GUI where you can walk around and interract with the hardware in a natural fashion. Volunteers?
Device description
Since XMPPWHFS is aimed towards real-world I/Os, we need lots of useful info that must be made available by each HAL
About the HAL
- name
- description
- location (GPS coordinates and/or description)
- icon? I think we don't really care about the HAL itself, it's just a way to conveniently group I/Os
About devices on each HAL
- variable name
- variable type and allowed values (int, float, enum..)
- I/O type (lock, temperature, humidity...). a more or less standard list must be written
- ro/rw flag
- unit (meters, seconds, °C..)
- update delay in seconds
- last update timestamp
- warn/alarm thresholds for event notification
- icon? maybe not necessary. one can be chosen from the I/O name or type.
Sample session
- To HAL
- This is to get the simple, human-readable output
help
- From HAL
rfid_reader: last RFID tag read door_lock: status of door lock lock_delay: how long should the door stay open temperature: tell me how cold it is outside
- To HAL
- Here, it should be a good thing to have flags such as force_update if bot supports it.
describe
- From HAL
- I suppose it would be nice to include output from the help command above. XML validity needs to be checked anyway. Too many line breaks are added on purpose for readability on the wiki.
<hal name='HalName' target='event_main' backup_target='event_backup'>
<description>This device is a sample that does many things and actually nothing</description>
<location lat='47°00N' long='8°00E' elevation=495>Main door of building on route de Genève</location>
<devices>
<device
name='rfid_reader'
attrs='ro'
type='rfid'
last_update_timestamp=1326310608
value='00EFC0B554' />
<device
name='door_lock'
attrs='rw'
type='enum'>
<value>open</value>
<value selected="selected">closed</value>
<value>locked</value>
<value>unlocked</value>
</device>
<device
name='lock_delay'
attrs='rw'
type='int'
last_update_timestamp=1326310915
value=4
unit='s' />
<device
name='temperature'
attrs='ro'
type='float'
last_update_timestamp=1326312490
value=23.5
unit='°C'
alarm_high=28.0
warn_low=12.0/>
</devices>
</hal>
- To HAL
temperature
- From HAL
<device name='temperature' value=23.5 />
- To HAL
door_lock unlocked
- From HAL
<device name='door_lock' value='unlocked' />
- To HAL
door_lock foobar
- From HAL
- format needs to be thought a little better here..
<device name='door_lock' value='open' />error: new value out of range</device>
Discussion must be done around where the values should go in the XML, and if the whole device XML string should be sent back when requesting a single value. I say it should, as it simplifies the code (and let's not care too much about the overhead)
Events
When an event is detected by a HAL (threshold exceeded for example), the HAL sends the info with the Pub/Sub mechanism. other bots can subscribe to events, and then decide what to do.
we'll get something like: (suggestions welcome!)
<device name='temperature' value=11.8>warn_low_value</device>
Obstacle
- lack of expertise and motivation to implement a client in a µC
- weak programming skills
Components
Software
Some things can can be handy:
- JabberBot in python
Hardware
to make XMPPHWFS as useful as possible, some hardware should be designed and the necessary firmware written
Software extensions
- communicate with Asterisk to send voice commands
- have some fun with XMMS2 / MPD
Schedule
as soon as possible
- design a smart way to handle events (scripting/rules interface)
- implement test HAL client/bot with Pub/Sub
- implement event_master with Pub/Sub
- implement ctrl_bot
when the above is done...
- implement web interface on ctrl_bot
- implement fs_bot
- implement HAL bot on µC (SuperCaptor!!)
