Stupid error - USB cable overriding current SD print job

[jimsx]

I've done this twice now (just my stupidity unfortunately) but its sooo annoying ....

So I have my laptop next to my M2 - I set everything up / copy code to SD card / set M2 to print from SD / select the code .... and off it goes happily printing.

I unplug the USB & power cables from the laptop & wander off to another room to carry on using it etc ... leaving the M2 whirring away.

A couple of hours or so later the printer is still happily going strong - I come back into the room, sit down at my desk, plug the laptop power cable back in & (not thinking!!) plug the USB cable that is lying on the desk next to the power cable in as well.... Sadly, this interrupt to the M2 overrides the current job from the SD card, and the printing stops half finished !! DOH! ....

I appreciate that I should just remember to unplug the printer end of the USB cable instead ... but is there any way to "un-pause" the M2 at this stage (simply unplugging the USB cable again doesn't work - its too late sadly)? Alternatively, is there a simple instruction that I can always add to any gcode saved to the SD card to basically say "once you start this job from the SD card - ignore any USB connection until you've finished!"

I'm guessing that I just need to retrain my brain - but thought I would ask the question ...

[Tim]

I'm pretty sure that plugging in the cable like that initiates a reset of the RAMBo, which means that the firmware will have no way of knowing where it was or what it was doing when everything stopped.

I found out (like you, the hard way) that the same thing can happen if you leave everything plugged in; I was doing this with my laptop, which after an hour or so of printing went into sleep mode. That's essentially the same as unplugging the USB. Then when I came back and tapped on the keyboard (that was the mistake), I woke it up, the USB established a new connection, reset the RAMBo, and everything came to a halt. Ugh.

What I did in that instance was to measure how much had been printed already, then printed the rest of it as a separate piece and glued them together. That only works in restricted cases, though!

[Mike Hunter]

Just my two cents:

I took a "cure" from my gaming experiences and set the (computer) power settings to never shut down drives, monitor or go to sleep, saving the power scheme to a new name. So far, I've been able to start the print and then go back to work on the (printing) computer while the M2 does it's thing. When I'm done working, I turn the monitor off manually and head upstairs. The vase I recently printed took 14 hours and all seemed well through the night print. Just my two cents

Mike H.

[insta]

I solved this problem by putting the M2 on the opposite side of the room from my computer, and filling the area around the M2 with spools and tools and crap so I can't fit a laptop there.

Always look for a meatspace solution before a software one

[jsc]

Going to take the opportunity to flog my suggestion of running OctoPrint on a RaspberryPi or Beaglebone Black. These are cheap $30 computers. OctoPrint is a web-based printer host, and is very civilized. Much more full featured than trying to run everything from an SD card through an LCD interface. The plus side is that since your computer is never connected to the laptop, you don't have to worry about drives spinning up or something going to sleep that will pause your print or kill it.

[insta]

The only problem I have with OctoPrint is the same problem I had with regular USB printing -- it's much slower than SD card printing. There's still a noticable slowdown around tight arcs and such.