Autostart

Autostart is available on printers with an SD card reader. If there is a file auto0.g, the printer will recognize it while booting, and perform its content. Thereafter, if there are files with increasing numbers, e.g. auto1.g, they will be done.

Use cases

• get rid of any start.gcode in the slicer. Because all these things can be done already if the printer boots. The advantage is that the slicer needs to know much less about the printer its printing on, as the startup procedure depends a lot on the printer, and can be placed there, and changed also for all gcode files on the printer at once. The disadvantage of that is that many slicers insist on having some heatup commands in their now superficial start.gcode. Also, some enjoy putting the e_steps_per_mm in it, which causes that one needs to have different gcode files for different printers. Using auto0.g, thats not necessary at all.
• have settings there. Autostart is an alternative place to store/set printer settings, with the option of changing them on a normal keyboard. While printing, they of course can be real-time changed like most other settings.
• Use printer in a kiosk mode, e.g. when its powered, start a print.
• Set the printer to a fresh start state after a failed print.

Possible Improvements

• It would be nice to also have a end.g, that is executed after a print finishes. I never took the time to implement this.
• it could be replaced by a macro system, where additional gcode files could be called from other gcode files. However, coding this is involved, as one needs to store the original file, and the position. Also, I see no way of having a macro system with a performance level, that e.g. layer change/extruder change can be done in sufficient fast speed. A similar system already exists in linuxcnc

History

The feature was created by bkubicek in a pizza powered hacking session at Protospace/Utrecht with Joris and the Ultimaker guys. The initial intend was to have a print started, as soon the printer was plugged in. (e.g. for coin-operated exhibitions).

Code History

There was an option to trigger the autostart sequence from the "prepare" menu. This was commented out by Daid while overworking the lcd code to a macro based system, as it was on first place in the menu, and only very few people understood the meaning and use for Autostart. In Okt. 12 bkubicek took the liberty to have prepare again in the menu, because he could live with having to call the first file of his sdcard for each print setup (auto0.g, obviously). However he could not live with having his auto0.g only accessible as the last file on the sd card, since now the sd card content is reversely sorted, with the goal to have new files rather on top.