Will the new features (power panic, filament runout, etc) work only while printing from an SD card?
A bunch of the new MK3 features are in different ways variants of "restart print where it was aborted". Power panic restarts where it was when power was lost. Filament runout restarts where filament ran out. Missed steps triggers rehome, and then restarts where the step was missed.
Will this still work if I'm printing from octoprint? Even power panic?
I can definitely see it working while printing from the SD card, since the printer itself is in control, but can it work with any other control methods? If I'm printing via usb, be it from octoprint, pronterface, or whatever, is it just withholding the acknowledgement for the last gcode command until the incident is handled? That can't really work for power loss, can it?
Re: Will the new features (power panic, filament runout, etc) work only while printing from an SD card?
Everything other than power panic should work fine with Octoprint as-is, the printer will just report "busy" via serial until it is done loading new filament or rehoming or whatever.
Octoprint would need a new feature added to recognize power panic mode via a serial message, store the current gcode file and position to restart from, then wait until the MK3 announces it is ready to resume from that point.
Even if the Pi is being powered by the MK3 it's unlikely the Pi could store the current position in gcode and then shut down gracefully before the MK3 PSU is drained, and you can easily damage the Pi's file system by pulling the plug without shutting down gracefully. So you would likely need a secondary power source to keep the Pi running long enough, such as a USB battery pack or a UPS (but that defeats the purpose of power panic).
Re: Will the new features (power panic, filament runout, etc) work only while printing from an SD card?
Where do we go to read more details about features like this for the MK3?
Is there anywhere? For those interested?
From the very limited information avalible, and I am probably reading far too much into it, but it sounded like the EINSY board outputs the power panic signal to the accessory header for the RP0W.
At ~7:05 Josef seems to mention there is a pin specifically for "Power Panic" on the accessory port.
Josef did say "We have a distribution that creates a hotspot” at ~7:55 does this mean they have their own flavor running on the RP0W? and hence might be able to sort out the power panic feature set?
Re: Will the new features (power panic, filament runout, etc) work only while printing from an SD card?
I suppose it - power panic in octoprint - can be done in several ways, but they definitely require custom work in the octoprint code. The same goes for any other control method.
Even if it is possible to pick up the power panic signal on a dedicated pin, and use the remaining 300 or so milliseconds to save state and which gcode line is waiting for ack etc, you would still depend on the printer to know exactly _where_ in that specific gcode command power was lost. (Maybe you sent a "G1 X10 Y10 E10 F1? That's gonna take a while, how do you know exactly where to resume if power got cut halfway?)
My guess is that since we depend on the printer anyway, and since the printer already saves state etc, the most efficient way is to just add a few custom gcode commands for fetching printer state (like "Ready" or "Printing" or "Awaiting user ack" or similar) plus the saved gcode index or something: "Last gcode line: 13284". Then octoprint, or whatever controller you use, could query those at every startup and just present the user with a "resume" choice if the status indicates that a resume would be possible.
It would be cool, but it sounds like a lot of work. 🙂
Re: Will the new features (power panic, filament runout, etc) work only while printing from an SD card?
Maybe the build in native wireless support on the 32bit board...
Re: Will the new features (power panic, filament runout, etc) work only while printing from an SD card?
When I think about Octopi support, assuming Octopi stays powered! here is my picture of it:
The octopi will tend to run well ahead of the actual print-head movements, filling the available buffer with gcode commands. (Just try to hit cancel sometime and watch the # of moves the printhead makes before stopping).
When a power panic comes, the Octopi can be warned, stop sending gcode, and expect a disconnect, and wait, and periodically attempt to reconnect. It would then need to query the mk3 as to the status, specifically: what was the final gcode executed. The mk3 has clearly saved enough information to uniquely identify the point within the file where it stopped, but it must communicate that back to the octopi in some way.
The pi could then ask for "reheat, rehome, raise to Z=xxx, move to final position, and continue from there".
This does require that the Pi have continuous power, and therefore a UPS or battery back of some kind. However, a UPS for a Pi is a very different proposition than a UPS for a printer. A very small UPS could last over a very long power outage, whereas trying to keep a printer going (with nozzle/heated-bed/steppers) would last a very short time.
Not saying its necessarily practical: I'm not sure they make tiny cheap UPSs that can keep a Pi up for an hour. I'm just used to the big ones that cost 3x-10x the cost of the pi in the first place.
Re: Will the new features (power panic, filament runout, etc) work only while printing from an SD card?
You could probably drive a Pi for hours on a regular phone powerbank, you don't really need a full ups. But the raspberry seen in the video above is mentioned to get power through a pin, not through the normal usb connection, so I'm thinking it will lose power at the same time the rest of the printer does?
Re: Will the new features (power panic, filament runout, etc) work only while printing from an SD card?
maybe a tiny UPS for Rpi0 will be the solution?
150mAh and charging board, rest has to be done in software,
Jose said something that they will make Octopi Prusa Edition distro for MK3, maybe someone from Prusa reads here and can evaluate Rpi0 UPS possibility for power cut.
Re: Will the new features (power panic, filament runout, etc) work only while printing from an SD card?
I was thinking external pi3, not internal mini-pi. The external pi3 with battery/ups would be fine, although it would require custom pi and mk3 code.
If the power is lost to the pi, tough to reliably recover.