Nodes for IDM and DUO
This package provides a set of nodes that will add support for IDM on your Node-RED installation. IDM (Inter Domain Messaging) is a middleware used to connect different types of hardware which uses different types of communication protocols and technologies.
For example, you can use IDM to receive the temperature of a RS-485 thermostat, and then send a command to a XBee controller that will switch off the cooling system, and also send a notification to your Smartphone using the Internet. IDM will handle the problems related to use three different technologies here (in the example, RS-485, ZigBee and WiFi/Ethernet, but it is not limited to these).
Along with the IDM nodes, this package also provides a basic set of data-types' nodes, called DUO (bool, byte, int, string, etc). Each type has two kind of nodes: client and servant. Using the client, you can send the payload to a remote servant (implemented somewhere: on an Arduino, a Raspberry Pi, another Node-RED, etc). The servant will allow you to receive this type of message.
For more information about IDM, see IoT infrastructure with IDM.
Installation of dependencies on Debian
First, set up the APT repository http://pike.esi.uclm.es using:
wget -qO- http://pike.esi.uclm.es/add-pike-repo.sh | sudo sh
Now, install the following packages:
sudo apt-get install idm duo duo-wiring-service
Overview of Nodes
The following is a list of the provided nodes, and its main features. For a more detailed explanation, see the node 'info' tab on Node-RED.
DUO data types
IBool client: it sends the payload (converted to boolean) to the configured object (specified by its
IBool servant: injects a message with the proper
false) when it receives an invocation.
IByte client: it sends the payload (converted to byte, range from 0 to 255) to the configured object (specified by its
IByte servant: injects a message with the proper
payload(a number, range from 0 to 255) when it receives an invocation.
IInt client: it sends the payload (converted to number) to the configured object (specified by its
IInt servant: injects a message with the proper
payload(a number) when it receives an invocation.
IString client: it sends the payload (as a strig) to the configured object (specified by its
IString servant: injects a message with the proper
payload(a string) when it receives an invocation.
Active client: establish the observer of a
DUO.Activeservant. Using the
Activeclient, you can attach an observer that will be notified about any change. Example: you have an
Activelight and you want to know when someone switchs it on or off.
Active servant: this is an
Activeservant, you can set an observer to it, and it will be notified when a new message (of the selected type) arrives.
IDM configuration nodes
ice-adapter: this is the object adapter where servant will be added. Here, you can specify the endpoints to listen on (for example, in TCP: host and port).
ice-communicator: this is the broker object for the middleware. Just create one using the default settings.
idm-router: this is the location (as an Ice Proxy) of the used
IDMRouter. This router will handle the message forwarding through your IDM network.
duo-wiring-service: a service that cand handle multiple observer setups.
Other useful nodes
toggle in: a simple toggle button to provide input from the Node-RED editor. It does not send a predefinded state, but changes its state on each click.
toggle out: a simple widget to show the payload of the last message. It changes its status to 'true', if payload can be coerced to
true, otherwise it will show 'false'.