Part III: Command-Line Printer Control

Command-Line Printer Control

Why click buttons when you can talk to the printer directly over serial? The Ender-3 V3 SE speaks G-code — every command the slicer generates, you can type by hand.

Option A: Raw Serial with picocom

sudo pacman -S picocom
picocom -b 115200 /dev/ender3v3se

You’re now connected directly to the Marlin firmware. Type G-code commands and see raw responses:

Table 1. Essential G-code Commands
Command	What It Does
`M105`	Query current nozzle and bed temperatures
`M115`	Print firmware version and capabilities
`M503`	Dump all firmware settings (steps/mm, acceleration, PID values)
`G28`	Home all axes (X, Y, Z)
`G29`	Run auto bed leveling (CR Touch)
`M104 S210`	Set nozzle temperature to 210°C (non-blocking)
`M109 S210`	Set nozzle temperature to 210°C and wait until reached
`M140 S60`	Set bed temperature to 60°C (non-blocking)
`M190 S60`	Set bed temperature to 60°C and wait until reached
`G1 X100 Y100 F3000`	Move to position X=100 Y=100 at 3000 mm/min
`G1 Z10 F300`	Raise Z axis to 10 mm
`G1 E10 F200`	Extrude 10 mm of filament at 200 mm/min
`M106 S255`	Fan on full (0–255 range)
`M107`	Fan off
`M500`	Save settings to EEPROM
`M501`	Load settings from EEPROM
`M18`	Disable stepper motors (lets you move axes by hand)

Exit picocom: Ctrl+A then Ctrl+X

If you’re inside tmux, Ctrl+A is likely your tmux prefix and won’t reach picocom. Instead, kill it from another pane:

# Find the PID holding the serial port
lsof /dev/ender3v3se

# Kill it
kill <PID>

G-code commands are case-sensitive — use uppercase (M105, not m105). Lowercase will return Unknown command.

Option B: pronsole (Full CLI Print Control)

pronsole is a dedicated command-line interface for 3D printers — connect, preheat, load G-code, and kick off prints without ever opening a GUI.

yay -S printrun
pronsole.py

The command is pronsole.py, not pronsole. Verify with: pacman -Ql printrun | grep bin

You will see two harmless warnings about dbus and psutil — these are optional dependencies for sleep inhibition and process priority. Ignore them.

Table 2. pronsole Quick Reference
Command	What It Does
`connect /dev/ender3v3se 115200`	Connect to the printer over serial
`gettemp`	Query current temperatures
`bedtemp 60`	Set bed temperature
`settemp 210`	Set nozzle temperature
`home`	Home all axes (lifts nozzle — use before cleaning bed)
`extrude 50`	Extrude 50mm of filament (use to test flow)
`load /full/path/to/file.gcode`	Load a sliced G-code file (no `~` expansion)
`print`	Start printing the loaded file
`monitor`	Watch print progress, temps, and ETA in real time
`pause`	Pause the current print
`resume`	Resume a paused print
`reset`	Reset the printer (use to cancel a failed print)
`off`	Turn off heaters and motors
`disconnect`	Disconnect from the printer
`exit`	Quit pronsole

pronsole does not expand ~. Always use the full absolute path when loading G-code files (e.g., /home/evan/3dprints/… not ~/3dprints/…).

There is no abort or cancel command. To stop a bad print: pause → reset → home → clean bed → load → print.

CLI-First Workflow

The full terminal-native workflow — slice in the GUI, then drive everything from the shell:

Daily workflow (CLI-first)

 1. Power on printer
 2. Clean bed with IPA
 3. Load STL into OrcaSlicer (flatpak run com.orcaslicer.OrcaSlicer)
 4. Select profile: Ender-3 V3 SE / 0.4 nozzle / PLA
 5. Adjust nozzle temp for your filament (check spool label)
 6. Click "Slice plate" → "Export G-code" → save to ~/3dprints/
 7. Preheat via picocom:
      picocom -b 115200 /dev/ender3v3se
      M104 S210    (nozzle)
      M140 S60     (bed)
      M105         (check temps)
 8. Kill picocom from another pane:
      lsof /dev/ender3v3se → kill <PID>
 9. Print via pronsole:
      pronsole.py
      connect /dev/ender3v3se 115200
      load /home/<user>/3dprints/<file>.gcode
      print
      monitor
10. Watch first layer — confirm filament is extruding
11. Walk away (monitor command shows progress remotely)
12. Remove print after bed cools to ~30°C

If printing via USB/serial, your computer must stay connected for the entire print duration. If the laptop dies or disconnects, the print stops. For unattended prints, use the MicroSD card method.