[FEATURE REQUEST]🦄GCODE Streamer Host definition for 3.X

[luc-github]

Time to define what host feature will be:
Basic description
1 - Read Gcode from SD
2- Send GCODE to printer FW via Serial
3 - Wait for ack
4 - if ack go to 1 / if error go to 2

Now need to clarify each part :

• Point 1 is no issue so far: just store file name / currentline
• Point 2 need more elaborate:
  1 - add Line numbering in command
  N1 G28
  Reset the line numbering is M110 N0 on Repetier / Marlin / Smoothiware
  2 - add command checksum for safety (all command char are XOR+*+checksum calculated)
  N20 M105*20
• Point4 : ack always use ok +line number
  ok 20
  if error on line number or checksum you get
  resend 20

Not sure if special command need to be handled (like @Pause) right now as it is not a host that have direct UI, but will be when Oled Screen is enabled as well as rotary encoder is supported.

One command is key: Emergency stop, to stop sending commands ans stop printer FW

[luc-github]

some update for command / answer according Firmware:
1 - smoothieware
which is quiet (nowait when idle), use N{New Line Position} M110 to reset, and resend error is rs N, M29 does not need checksum, send ok without line number

2 - Marlin Kimbra
which is not quiet (send wait when idle), use M110 N{New Line Position} to reset, resend error is Resend: , M29 need checksum, ok does not use line number

3 - Marlin
which is quiet (no wait when idle), use M110 N{New Line Position} to reset, resend error is Resend: , M29 need checksum, ok does not use line number

4 - Repetier
which is not quiet (send wait when idle), use M110 N{New Line Position} to reset, resend error is Resend: , M29 does not need checksum, ok use line number

[luc-github]

Basic GCODE host functions are now available
they will be used for the autotstart feature, the [ESP700] command and Serial Upload
the host features will be improved later if necessary

[luc-github]

Next steps to work on for proper gcode host support

• should not be blocking e.g. screen update. external commands for pause/stop/etc..., may be by using separated task
• should be able to wait for delayed answer/ next command: G4 or M116 or M190 or M109, may be by disabling time out for these command
• handle printer error if not heating or defective sensor
• allow auto script for pause/stop/etc...
• display file stream process
• TBD