openhab_msgs

See openhab_msgs on index.ros.org for more info including aything ROS 2 related.

Contents

Install the openhab_msgs
Explanation
1. Item Types
2. Command Types

Message types for the openhab_bridge. It is based on the Item Types and Command Types of openHAB.

Install the openhab_msgs

In the next step you have to install the openhab_msgs in your catkin workspace:

cd ~/catkin_ws/src
git clone --branch <branchname> https://github.com/Michdo93/openhab_msgs
cd ~/catkin_ws
catkin_make

Please replace <branchname> with your branch, as example kinetic-devel, melodic-devel or noetic-devel.

Explanation

For subscribing from openHAB a State Message Type is used and for publishing to openHAB a Command Message Type is used. For an item type (openHAB), this means that two message types (ROS) are used in this event bus.

Type Name	State Message Type	Command Message Type
Color	openhab_msgs/ColorState	openhab_msgs/ColorCommand
Contact	openhab_msgs/ContactState	openhab_msgs/ContactCommand
DateTime	openhab_msgs/DateTimeState	openhab_msgs/DateTimeCommand
Dimmer	openhab_msgs/DimmerState	openhab_msgs/DimmerCommand
Group	openhab_msgs/GroupState	n/a
Image	openhab_msgs/ImageState	openhab_msgs/ImageCommand
Location	openhab_msgs/LocationState	openhab_msgs/LocationCommand
Number	openhab_msgs/NumberState	openhab_msgs/NumberCommand
Player	openhab_msgs/PlayerState	openhab_msgs/PlayerCommand
Rollershutter	openhab_msgs/RollershutterState	openhab_msgs/RollershutterCommand
String	openhab_msgs/StringState	openhab_msgs/StringCommand
Switch	openhab_msgs/SwitchState	openhab_msgs/SwitchCommand

Item Types

To subscribe the items from openHAB or to publish an item including a command to openHAB you need the appropriate message types. These are based on the Item Types and Command Types of openHAB.

The Item type defines what kind of state can be stored in that Item and which commands the Item will accept. Item types are comparable to basic variable data types in programming languages. Each Item type has been optimized for a particular kind of component in your smart home. This optimization is reflected in the data and command types.

Available Item types are:

Item Type	Description	Command Types
Color	Color information (HSB)	OnOff, IncreaseDecrease, Percent, HSB
Contact	Status of contacts, e.g. door/window contacts. Does not accept commands, only status updates.	-
DateTime	Stores date and time	-
Dimmer	Percentage value for dimmers	OnOff, IncreaseDecrease, Percent
Group	Item to nest other items / collect them in groups	-
Image	Binary data of an image. This means a base64 encoded string	-
Location	GPS coordinates	Point
Number	Values in number format	Decimal
Player	Allows control of players (e.g. audio players)	PlayPause, NextPrevious, RewindFastforward
Rollershutter	Rollershutter Item, typically used for blinds	UpDown, StopMove, Percent
String	Stores texts	String
Switch	Switch Item, used for anything that needs to be switched ON and OFF	OnOff

Command Types

In the last step we take a closer look at the Command Types and its Range of Values.

Command Type	Range of Values
Decimal	<int> or <float> So theoretically the max values of an integer or float in Java.
HSB	"<hue>,<saturation>,<brightness>" <hue>: 0...360 <saturation>: 0...100 <brightness>: 0...100
IncreaseDecrease	"INCREASE" or "DECREASE"
NextPrevious	"NEXT" or "PREVIOUS"
OnOff	"ON" or "OFF"
OpenClosed	"OPEN" or "CLOSED"
Percent	0...100
PlayPause	"PLAY" or "PAUSE"
Point	"<longitude>,<latitude>,<altitude>" <longitude>: -180.0...0...180.0 degrees <latitude>: -90.0...0...90.0 degrees <altitude>: <float> in meters. There are locations that are below sea level and there are mountains that are quite a bit higher. A limit value is not known.
RewindFastforward	"REWIND" or "FASTFORWARD"
StopMove	"STOP" or "MOVE"
String	<String> So theoretically the maximum size of an String in Java.
UpDown	"UP" or "DOWN"

A command type like OnOff is ultimately an enum and contains the strings "ON" and "OFF" as constants (this is why they are written in UPPERCASE), so the other enum commands actually look the same. This means that there are only two constants per each enum type.

The Command Types are only used within openHAB. The openhab_msgs also have these enums in their field description, but you may have to work with a string in parts of your program!