Power fails restore feature

Tech3D

Please add power fail restore (restore print where left if accidentally main power is gone) feature. Prusa i3 MK3 new printer has this feature and it is great feature.

Repetier

How do they solve detecting that there is no power and how do they store current position? Without power the processor is not running any more. The solution I know is a hardware addition detecting this and giving power for a short time to save position, but without this I don't see how to do this.

Tech3D

Maybe there is a way if we store every new GCODE line in a file on SD card when it sends to 3D printer... So every time new GCODE command will be sent it will be saved in SD card and at the end of print that file will be removed from SD card. Now if power fails, on machine restart firmware will read SD card for backup file, if it finds file it means there was power failed and it will start printing from that last command...
Or on the other hand gcode file will be updated each time command is sent to printer and that command will be deleted from GCODE file. So when restore print will be started from GCODE, it will be the last position of file...

Repetier

Don't think that will work. That means you print with host/server and then they need to know where it stopped. Maybe if they would do it and the filesystem is not corrupt from power out of computer they can restore. It is not easy especially since we can normally not home but do not know xyz position at restart of printer.

Tech3D

does the Resume on power Failure function is added now in Repetire Firmware...???
Now Marlin has also included this feature...

Repetier

We have it in combination for printing over Repetier-Server but not for sd print.

Backu68

I have my printer and raspberry on an APC battery backup. There is software for linux to interface with the APC. If we can get a backend command to power- fail pause printing, and resume, that would be helpful.

Tech3D

Yes battery backup method is good. It will use a pin on Arduino for the detection of the presence of main power and whenever the power goes off the 3d printer's system goes into pause. And when the power came again it start printing again. But in the absence of power the battery should power the Arduino continuously so that it do bot forgot it print job.

Tech3D

But I think it is not a bad option if we use Arduino's EEPROM to store the current state of gcode of the print job and update and store the state in real time in eerrom alongwith the 3d printing job running. And whenever the power goes off and when power came later and on boot the printer check the state of stored gcode in the eeprom and if it finds that the previous job was unfinished it start the job right at that point. It could not be not so must accurate logically but it is a good step i think.
Marlin firmware uses almost same algorithm in its resume on power failure feature.
I am using repetier firmware from a long time I like it very mush so I want if repetier firmware cound provide this feature it will be grate.

Repetier

In 1.0.4dev we have a similar option, but it only works in combination with repetier-server. Firmware will issue a message that power goes down and move to a save park position - if you stay you get a blob. It also stores last print position and if reached park position in eeprom to help server to continue exactly at that position.

This also helps on lost usb connection and will restore condition and save print.

Maybe in V2 we will get the capability also for sd print.

Tech3D

That is great. Thanks a lot. Waiting for SD option.
Meanwhile I will try Repetier-Server option.