OK I have sorted the partition issue thanks to UniPi tech support: manually resizing the SD card partition using gparted on another Linux system.
However I'm still looking for a guide to the 'official' way to upgrade nodeJS, npm and NodeRed on a UniPi Neuron. I'd like nodeJS 18 and Node-RED 3 if possible. The only documentation I came across regarded nodeJS 14 as 'new'!
@AVsetula Just today I tried updating my Neuron to the current Node/Node-RED versions. This was just after first boot from an SD card flashed with the neuron-node-red_image-20220607.0.zip. The update mysteriously failed, and it took me a while to realise that the problem was I had run out of disk space.
It seems the automatic resize of the rootfs that is supposed to happen at first boot did not, so I only have ~ 2GB of disk! Is this a known problem, or has something else gone wrong? I'm using a '16GB' RasPiKey, which is eMMC-based, but looks exactly like a normal SD card: at least it did to Balena Etcher. On the Neuron, fdisk tells me:
unipi@M203-sn499:~$ sudo fdisk /dev/mmcblk0
Welcome to fdisk (util-linux 2.33.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): p
Disk /dev/mmcblk0: 14.6 GiB, 15634268160 bytes, 30535680 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x5f965ddd
Device Boot Start End Sectors Size Id Type
/dev/mmcblk0p1 8192 212991 204800 100M b W95 FAT32
/dev/mmcblk0p2 212992 4194303 3981312 1.9G 83 Linux
Command (m for help): F
Unpartitioned space /dev/mmcblk0: 12.6 GiB, 13489930240 bytes, 26347520 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
Start End Sectors Size
2048 8191 6144 3M
4194304 30535679 26341376 12.6G
(The reported capacity seems a bit low?) Is there a way to manually resize the partition, or should I just re-flash the RasPiKey and try again (there is nothing valuable on it as yet)?
It seems this was fixed 29th April 2021
@AVsetula Thanks for your reply. To help troubleshooting, I made up an RJ45 connector breakout and viewed the 'data out' pin on an oscilloscope. It soon became clear that the problem is one of intermittent connection. I connected the scope at the end of the device chain (socket 8 on the hub) and if I connect all the intermediate sensors, and tape their cables to the bench so there is no strain on the RJ45 connector, all is well. I can see nice sharp 0V to 5V data transitions on the scope.
But, any movement on the cables causes an intermittent loss of contact, immediately apparent from the 'illegal' voltages that appear on the scope display.
I have disassembled the hub and buzzed out all the solder joints: no problems. The issue seems to be either with the RJ45 plug/socket connection, or with the sensor cable/RJ45 plug crimp integrity.
It doesn't help that the insulation on the temperature sensor cables is extremely stiff, so that any movement of the cable puts strain on the RJ45 connector.
I think I will need to arrange for cable clamps to hold the sensor cables in place. The hub will be mounted in a plastic box, so this is feasible: I should be able to 3D-print something.
@nfmax
I have a Neuron M203, an 8-port 1-wire hub, and 6 1-wire temperature sensors with 1.5m leads type Product code: 2014019. This has been in storage for a couple of years, but now I'm trying to set it up. I'm using the original Node-RED OS:
Linux M203-sn499 5.4.72-v7+ #1356 SMP Thu Oct 22 13:56:54 BST 2020 armv7l GNU/Linux
The problem is 1-wire operation is extremely unreliable. Sometimes no sensors at all appear in the UniPi control panel, usually one or two appear, twice now I have seen all six.
Sometimes an extra sensor will spontaneously appear. Sometimes one or more sensors will just stop working. Rebooting the Neuron may make things better or worse.
It is usually a bit more reliable with only one sensor connected, but often even a single sensor is not found, although it may appear after a few minutes.
I'm using a 3m long cat5 cable to connect between the UniPi and the hub. I have checked it is wired correctly as the documentation states.
What prompts the UniPi to search for 1-wire devices, and how often does this occur? Can I force a search? Is there any debug output that might help, or do I just have faulty hardware?
How do I read values from this type of sensor in the UniPi Node-RED image? I have tried using 'Temp' as the device, and the bus address as shown by the UniPi Control Panel as the circuit, but get no output. I can see messages from this device coming from the websocket node.