Xkeys Write Data node for Node-RED with Dynamic Control Data Protocol (DCDP)
This is another in a collection of Node-RED nodes which enable access to X-keys physical devices.
It is planned to have a dedicated Node-RED node for each X-key event of interest (button, jog, joystick, etc.). These will communicate, using MQTT, with a lightweight X-keys server, whose sole purpose is to mediate access to any physically attached X-keys devices.
This _xkeys\_writeData_ node enables arbitrary command codes to be written to specific X-keys devices.
This node requires _dcdp-server_ version 0.1.1 to be running. Please follow the instructions at the _dcdp-server_ development repository to install it or, to upgrade an existing installation, see the _dcdp-server_ upgrade instructions.
The _node-red-contrib-xkeys\_writeData_ node itself is best installed from Node-RED's Palette manager. Go to the Palette manager's Install tab and search for _node-red-contrib-xkeys\_writeData_; then Install it once found. If not found, press the _Refresh module list_ button (two semicircular arrows) and search again.
When installed, a new _xk Write Data_ node will be found in the palette tab in the dedicated _Xkeys_ category.
In addition to setting the command code to send to a device, the node's configuration editor must be used to explicitly set the target X-keys Device, as well as the Unit ID of the device. After Node-RED's Deploy button is pressed, the node's own built in button can then be used to send the command to the nominated device. A command code may also be provided to the _xkeys\_writedata_ node input from the previous node in a flow. In this case the previous node must include a "commandcode" field in the msg.payload e.g.
``
{"commandcode": "[0,206,0,1,72,101,108,108,111,32,87,111,114,108,100,32,32,32,32,32]"}
while the _xkeys\_writedata_ node itself must still be configured with a valid _pid\_list_ (or _pid_) and _unitid_.
When configuring the node, a drop down list of possible devices shoud be available. If not, instead displaying just a note to Press Deploy button to see device list, first follow that advice. If that is unsuccessful (still no list of possible devices), then check the status of the dcdp-server by running the command sudo systemctl status dcdp-server in a terminal. Typical output of a normally running dcdp-server will be:`
pi@pi3b:~ $ sudo systemctl status dcdp-server
ā dcdp-server.service - Run dcdp-server as background service
Loaded: loaded (/etc/systemd/system/dcdp-server.service; enabled; vendor preset: enabled)
Active: active (running) since Thu 2021-10-14 09:31:55 AEST; 23h ago
whereas a non-running dcdp-server will show something like:
pi@pi3b:~ $ sudo systemctl status dcdp-server
ā dcdp-server.service - Run dcdp-server as background service
Loaded: loaded (/etc/systemd/system/dcdp-server.service; enabled; vendor preset: enabled)
Active: failed (Result: timeout) since Fri 2021-10-15 08:41:37 AEST; 19s ago
If necessary, (re)start the dcdp-server with