OctoPrint On Air is a roughly monthly live broadcast done by me (Gina Häußge)
for all Patrons on the Patreon campaign pledging at the $5 perk or above.
Attendees can ask questions which will be answered on air and I also report
what’s been going on in the background, what happened, what the current
challenges are and what the near future holds, plus talk about whatever else
might be interesting in the world of OctoPrint.
Regarding the 1K (maybe 10% of the users) running their printers with active undervoltage conditions, a number of things could be contributing to this.
of course, it could be the power adapter that powers the Raspberry
it could be the line voltage at the wall which is under-powered (this routinely happens in office buildings); a UPS would help in cases like this
it could be that too many things have been plugged into the Raspberry (webcam, TFT or possibly an HDMI monitor, keyboard, mouse)
but perhaps we might have overlooked that 5V could be bleeding out over the serial connection to some of these printer boards
The 4th one isn't as crazy as it seems. My recent autonomous tank project taught me a lot about this.
Raspberry Pi Zero W -> non-USB serial -> Arduino Mega 2560 board
The power LED on the Arduino in this case would try to light up when the Raspberry was powered. The voltage on the serial line was being felt over on the other board, acting as a power sink in this case.
I know that my Robo controller board has a jumper which would prevent the board from sinking 5V from the serial connection but I couldn't tell you about other boards.
Also, there's a difference between a DC charger and a DC adapter. The output voltage on an adapter looks like a horizontal line if you see it on an oscilloscope. The output from a charger isn't expected to be a clean horizontal line; it's expected to be something which wobbles in the approximate area of the output voltage.
You're right, knowing the RC participant numbers is big. That's cool. Congrats Gina.
The modern Pis don't run on 2.4A and don't like long USB cords, I'm not surprised we're seeing so much undervoltage. Line voltage fail seems weird, 'guru, generally a wall wart will work down to 80v or so. More likely, voltage-wise, people should be using 5.2v adapters. Still, wonder if at some point we'll have to disable the 'print' button for undervoltage.
I see stats.octoprint.org is online. But it has a password oh well.
I'm really curious about the 24h stats, about turning off/on. And that would hurt with SD cards, I'd guess. I assume the heatmap below the geomap will make it more clear. Perhaps we should send uptime in pisupport, perhaps some disk info too.
Safety 'screaming'- if you decide to allow prints, don't do it with a control panel checkbox. Require approval for every print.
I'm also thinking about how to detected unclean shutdowns of the server and popping up a warning on next start about that. Something like setting a flag in the shutdown routine should do it. The only problem here are windows systems since there I have run into issues with the shutdown routine not being called reliably, but if push comes to shove I'll just ignore windows for that functionality. It's only in 1% of installs anyhow:
That would be the fallback solution. Getting another public Grafana instance up and running and pushing snapshots of the various dashboard there via cronjob shouldn't be that tricky though - I just have to find half a day or so for it
In businesses, I'm usually the guy who volunteers to review the building's power, remove wall/box plates and then make a sad face when I see what's left of the original wiring.
common mismatch between the metal used in the wiring and that of the connecting screws for the outlets themselves resulting in galvanic corrosion, added resistance and dropped voltage...
...which then leads to a cycle of added heat, more resistance, more heat and eventually a catastrophic failure of the remaining wire, arcing and more heat
this would effect anything on a particular circuit but most significantly the outlets which are arcing
similar problem related to damp environments like garages and basements (typical homes for 3D printers)
over-populated circuit breaker boxes (building designs 20 years ago could never have imagined the needs of today) which then deliver less than the expected voltage to all the outlets downstream
co-existence of compressors (refrigerator, air conditioner) and halogen lighting (startup power needs) on the same system
For a 115VAC system, I routinely see anything in the 106V-109V range here in California businesses as delivered to the wall plate. To a 5V power adapter that means the low end sees 4V output instead, so it's significant.
You're seeing a lot of retro stuff. I checked a couple of adapters nearby, which are rated at 100-240v. Older amp or less PSes are probably linear, but modern stuff would put out too much heat. Quick glance gives the same range for the CanaKit power adapter, as close to a "standard" Pi power supply as I can imagine.
I'm so used to everything being multi-voltage that I don't even check before plugging it in when I'm in Europe. Easy rule of thumb is anything multi-voltage is using a SMPS and doesn't care about wide variation.