#GCODE print time estimation, based on Marlin 3D Printer Firmware

Based on an older version of the firmware from https://github.com/davr/Marlin/tree/estimate/Marlin

Changes:

• cleanup - removed all unnecessary codes
• check if the file parameter exists
• change the output

Used with https://github.com/MoonshineSG/Simplify3D-to-OctoPrint, it will send JSON

{"human": "10 hours 56 min 12 sec","machine":39372.572320}

as user meta data when uploading it to Octoprint.

https://github.com/MoonshineSG/OctoPrint-Mobile (an iOS Octoprint UI) makes use of this to provide a better estimation.

The mobile ui plugin adds the time waiting for extruders to heat up, by making use of M808 start custom action. Add M808 start as the last line in the custom starting script after the bed & nozzle warm up commands M190, M109. This needs Marlin firmware change to handle M808 (which will echo whatever parmeters sent with M808 prefixed with //action: - see https://github.com/MoonshineSG/Marlin/blob/RCBugFix/Marlin/Marlin_main.cpp#L6311 and https://github.com/MoonshineSG/Marlin/blob/RCBugFix/Marlin/Marlin_main.cpp#L7128)

gcode_estimate compiled for OSX El Capitain (10.11.4)

Note: To specify speed / acceleration settings see the comments from the original developer at OctoPrint/OctoPrint#270 (comment)