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IoT with the bestParis 2016-01-16
VSCP
Åke HedmanMaintainer VSCP (Very Simple Control Protocol)
Founder Paradise of the Frog
Disclaimer
VSCP is not seeking world domination
Does not handle the 15 second rule well
Stay foolish – Be hungry
State of things
● Vertical, vertical, vertical, vertical...● A lot of transport mechanisms.● A number of standardization efforts (AllSeen
alliance, IPSO alliance, Tread Group, Eclipse IoT, etc etc etc )
● IoT???????
IoT - What is it?
● INTERNET of THINGS● INTERNET = INTER + NET● THINGS● Not just wireless, not just protocol A, not just...● Connecting nets together. ● Intranet of things● In the end its just about Connecting things together● Enables Big Data mining.
Problems
Problems
● We must know that a device is there and what it can do (Discovery).
● Devices from different manufacturers must understand each other (Message format).
● We need a common way to tell devices what to do (Configuration).
● We need a common way to update firmware of the devices (Firmware update).
● SECURITY!!!!
Real world
Messages
Measurements
Measurements
42
Measurements
● “Answer to the Ultimate Question of Life, the Universe, and Everything.” - The Hitchhiker's Guide to the Galaxy by Douglas Adams
● The approximate length of a marathon in kilometres
● The atomic number for Molybdenum● ...or other things.
Measurements
● It's still 42 if sent over a MQTT channel.● ...or in an UDP packet.● ...or sent over a highly secured link.● ...or sent over a wireless mesh network.● ...or sent from a mainframe.● ...or received by the smartest person/machine
in the universe.
Measurement
● So the conclusion is that the receiver has to know that “42” is a temperature measurement for the value to be useful at that receiving end.
● So we have to add “information” to the value.
Measurements
So if we know it's a temperature measurement?
Measurements
Typically solved as
by JSON
{
“measurement”: {
“type”: “temperature”,
“value”: 42,
}
}
or in XML
<measurement>
<value type=”temperature”>42</value>
</measurement>
Measurements
Still not perfect
Measurements
Typically solved as
by JSON
{
“measurement”: {
“type”: “temperature”,
“unit”: “kelvin”,
“value”: 42,
}
}
or in XML
<measurement>
<value type=”temperature” unit=”kelvin”>42</value>
</measurement>
Measurement
● Wasteful. ● Over air/cable.● In RAM of low end device.● On resources on low end device.
Measurements - VSCPTypically solved as
in JSON
{
“measurement”: {
“head”:0,
“class”: 10,
“type”: 6,
“unit”: 0,
“sensorindex”: 0
“coding”:
“value”: 42,
}
}
in XML
<measurement head=”0” class=”10” type=”6” >
<value type=”temperature” unit=”kelvin”>42</value>
</measurement>
Measurements
● SI system.● Well defined data.● Compare with web.
On/Off
● Same thing. ● Some send literal “on” and “off”● Others send literal/binary “0” and “1”● Even others send “في” and “بعيدا”
● Or even “ 上の” and “ オフ”● Hard to know what a device is expecting and
equally hard to understand what to do when received.
VSCP way
Start with the lowest level
How VSCP does it
● Lowest common denominator is the CAN frame● CAN packet size (8-bytes) .● Binary
How VSCP does it
● Two levels. Level I and Level II. Mainly differ in packet size.
● What other calls messages we call EVENTS● VSCP is an application level protocol.● On,off,TurnOn,TurnOff etc etc etc etc has a well
defined format.● Events identified by a class (sort of group) and a
type. Temperature for example is CLASS1.MEASUREMENT, Type=6
How VSCP does it
● VSCP Level I have a maximum of 512 classes defined (alarms, measurements, information, protocol,.......growing) each with 255 possible types.
● VSCP Level II have a maximum of 65536 classes and where each can have 65535 types.
Turning on “something” in VSCP
● So turning on “something” in VSCP is done by sending a CLASS1.CONTROL, Type=5 (TurnOn) event .
● Most often the device(s) that is turned on reply with CLASS1.INFORMATION, Type=3 (On) Event(s) .
● Similar CLASS1.CONTROL, Type=6 (TurnOff) event turn “something” off and expects CLASS1.INFORMATION, Type=4 (Off) Event(s) .
Requires content of Level 1 event
● Flags: 7 bits (priority, hardcoded). ● VSCP Class: 9-bits.● VSCP Type: 8-bits● Nickname: 8/16/(24/32)-bits.● Data: 0-8 bytes.
CAN4VSCP
● 32-bit id.● Nickname is 8-bits. Can be discovered or hard
coded.● 0-8 data bytes.
Other events
TurnOn Event over CAN4VSCP
● 32-bit id containing priority, class,type and nickname described here.
● VSCP-Class =30 (CLASS1.CONTROL)● VSCP-Type=5 (TurnOn)● Three data bytes● Byte 0: User specified. Usually set to zero.● Byte 1: Zone● Byte 2: Subzone
But TurnOn can look like this to
in JSON
{
“vscpevent”: {
“priority”:0,
“vscpclass”: 10,
“vscptype”: 6,
“guid”: “”
“data”: {0,0,0}
}
}
in XML
<vscpevent priority=”0” vscpclass=”30” vscptype=”5” guid=”” data=”” />
General VSCP Properties
● Application level protocol.● No server needed.● Not addressed.● Free.● Open.● KISS (Keep It Simple Stupid).
Discovery
Discovery
● How do we know things are available?● Beacons● Heart beats
How VSCP do it
● Every node send a heartbeat at least once a minute.
● Possible to scan for nodes.● When a node identify itself it itself contain the
key to its configuration and usage.
Configuration
Configuration
● We always need a way to tell things what to do and how to do it before they become useful for us.
● Pre Windows and HAL sometimes 30 diskettes for drivers one for the application. HAL was the thing that made it happen.
● Just as HAL abstracts hardware we need abstractions for black boxes.
The black box
The black box
The black box
● And they all are all different inside.● They (almost) always need a manual to
understand how to configure them.● “Where is the manual...”●
How VSCP do it
How does VSCP do it?
● The IC Circuit is a successful black box In the real world.
● Scale well● Can talk to other IC's● Is configured with “switches” or registers.
Register Abstraction Model
● So a VSCP black box have a set of registers. Standard registers. User registers.
● Every register is 8-bits wide. ● There is 128 registers (Standard registers)
reserved on every node that must be there.● Level I: 128 * 65536 registers that the maker of
the device can use.● Level II: 32-bit address pointer.
Register Abstraction Model – Standard registers
● GUID – Globally unique id.● Pointer to MDF (Module description file).● Boot loader algorithm.● Hardware version.● Firmware version.●
GUID
● GUID is a 128 bit globally unique id that identify a unit.
● A nickname (8/16 bit) can be used on a local bus to save bandwidth..
● GUID's can map to many other globally unique id's. See Specification.
● GUID series can be requested for free from [email protected]
Module Description File (MDF)
● XML-file that describe the module.● Normally fetched from an Internet location but can be fetched from the
device directly to.● Defines registers and there content.● Defines abstractions (high level data types).● Define events sent by node and there content.● Define actions the nodes decision matrix can generate.● Defines setup wizards.● Firmware update information.● Points to contact info of maker, manual for device, firmware, pictures, is
multilingual and a lot more.
Abstractions
● Present register content as high level data types.● bool● string● long● float/double● guid● Etc etc.
Decision Matrix
● Optional.● Configure what action a node should perform
when it receives an event.● For example turn on relay one when a TurnOn-
event is received.
Decision Matrix
● Optional.● Configure what action a node should perform
when it receives an event.● For example turn on relay one when a TurnOn-
event is received.
Setup wizards
● A assisted guide to follow, to get a specific functionality of a device, described in XML.
● Report temperature in degrees Fahrenheit every minute and alarm me if temperature goes over 77 degrees or below 32.
● Can be read and served by all UI's (phones/PC's/tablets/browsers/applications/...)
Firmware update
Firmware update
● Standard algorithm.● Device specific algorithms.● Who can/is allowed to do it.● Protect copying of products.
Implementation
● 2.5K overhead in flash. ● A few bytes of RAM● Can be implemented alongside proprietary
solution.
Security
● SSL (TCP/IP)● Aes (Multicast, raw ethernet, wireless)● Other.
Multicast
● Used for discovery.● Used to form subnets/groups.
Raw Ethernet
● No need for a tcp/ip stack.● Very low on recources.● Do normally not pass a router.
For the end user
● A node is discovered.● Get MDF from it. ● Configure the node.● Make it interact with other nodes.● Use wizard to get help to set up a device to do
“something”.● Same every time.
Tools
● The VSCP daemon● VSCP Works● VSCP Helper library● Javascript library with HTML5 widgets (websocket)● Firmware code for multiple platforms.● Examples.● Windows/Linux(Pi/Beaglebone)
The VSCP Daemon
● The VSCP “server”.● TCP/IP interface. This interface is a superset of a general tcp/ip interface that
can be implemented by devices.● Drivers for everything can be connected. Can be used to abstract non “VSCP
things” to look like they are “VSCP things”. Or the other way around. Many driver available.
● Multicast interface.● Advanced internal decision matrix.● Built in webserver.● Websocket interface● REST interface (plain text/CSV/JSON/JSONP/XML).● Soon built in MQTT and CoAP support.
VSCP Works
● Investigate what is happening on local or remote bus.
● Interact with nodes.● Discover nodes.● Configure nodes.● Load firmware into devices.● And more...
VSCP Helper library
● C library for Windows/Linux● Bindings for many programming tools available
or on the way.● Many functions to handle VSCP related tasks.● Can be used to connect to a remote VSCP
daemon in an easy way.
Javascript library
● Interface the efficient websocket interface.● Buttons.● Gauges.● Diagrams● Tables.
...and more
● A lot more.
The End
● Contribute to the project (http://www.vscp.org)● Vote for VSCP in Postscape IoT Open source award
http://iotawards.postscapes.com/2015-16/top-iot-open-source-project
● Documentation is here http://vscp.org/#documentation● Getting started guides is here
http://www.vscp.org/wiki/doku.php/howto/start● Software is here
https://github.com/grodansparadis/vscp/releases● Thanks
