1) I can not access to the NodeRED application¶
It could be one of the following causes:
Cause 1: Wrong configuration in the Node-RED flow, which causes the Node-RED to crash.
Solution: Execute the following command in order to check the logs for the error causing the crash:
journalctl -f -u node-red -n100
Cause 2: Node-RED watchdog timeout is too low. It could happen if many components have been installed on the Node-RED palette, causing it to take a long time to load, until the Node-RED watchdog ends up restarting the service.
Solution 2: Execute the following steps in order to change the time of actuation of the watchdog:
Step 1. Access the file
Step 2. Modify the parameter
WatchdogSecwith the desired time of actuation of the watchdog.
Step 3. Execute the following commands to reload the systemd deamon and restart the Node-RED service:
systemctl daemon-reload systemctl restart node-red
For further information about the watchdog, please check here.
Cause 3: There is some process that monopolizes the CPU.
Solution 3: Review the processes that are running using the
top command in the shell.
2) Sometimes Node-RED restarts for no reason.¶
Cause: Node-Red stucked due to incorrect configuration or programming in the Node-RED flow.
Solution: Execute the following command in order to know what is actually causing this:
journalctl -f -u node-red -n100
3) npm WARN: npm does not support Node.js v8.17.0¶
Cause: New version of npm have updated, and it is no longer supported on the node.js version of the system.
Solution: Reinstall original version of npm:
opkg install nodejs-npm --force-reinstall
4) gyp ERR! stack Error: not found: make¶
Cause: Some Node-RED packages require the native compiler in the eManager, such as node-red-node-sqlite.
Solution: Install native compiler package:
opkg install packagegroup-core-buildessential
Finally, restart the node-red service and try again to install the node in Node-RED:
systemctl restart node-red
5) TypeError accessing to a hardware module¶
Common error messages are:
- Error getting analog input...
- Error getting digital input...
- Error activating relays...
Cause: More than one hardware module request message ocurred at a time, and therefore a collision has occurred.
Collisions can occur when at the same time, on the one hand, a request is made to a hardware module, while another module generates an event from an input.
Solution: If possible, decrease the frequency of polling requests, to minimize collisions.
6) Missing node modules:
Cause: Node-RED community has published a new version of a package that is no longer compatible with Node-RED version that eManager incorporates. In this example,
<node-red-node-name> corresponds to
<node-red-node-dashboard> and the
<version> in the title corresponds to
When you try to update the version of one of the Node-RED nodes in the list below and the version is higher than the one supported, the error message shown in the capture is displayed.
Solution: Reinstall the previous version. To do so you need to execute the following commands:
cd /var/lib/node-red npm install <node-red-node-name>@<version> systemctl restart node-red
In this example, to reinstall the previous version
node-red-node-dashboard and the
List of last versions compatible with Node-RED 0.20.8
7) npm ERR! code EAI_AGAIN¶
Cause: There are some new version the Node-RED community has published for some nodes that are not compatible with the Node-RED version the eManager incorporates. When you try to install some package with a higher version that the one supported, this error occurs.
Solution: Manually, install the packet with the last version compatible with the Node-RED version the eManager incorporates. To do so you can follow the instructions detailed here.
If you want to know the last versions compatible with Node-RED 0.20.8, please check here.
8) Nothing provides requested
Cause: If you try to install a specific package and the Internet connection is broken during this process, it could happen that some parts of the package are already installed while others are not. In this case, an error similar to the one shown in the image may appear.
Solution: You must clean the files cache using:
And reinstall the package using:
opkg install <package_name> --force-reinstall
In this example
<package_name> is python-pkgutil.