This article is about the OT-One.

It's no-longer sold or actively supported by Opentrons, but we've kept this article here to help existing users. Please see our OT-2 Support articles for the most up to date information!


Our board is a G-code interpreter, compiled here is a list of the G-codes that are currently supported and you may find useful for troubleshooting:

Materials needed:

  1. Computer equipped with supported operating system: macOS 10.11+, Windows 10, or Linux

  2. A/B cable (provided with your robot)

  3. CoolTerm Software (download for free from link below)


  1. Download the free CoolTerm software 

2. Make sure you are disconnected from the Opentrons app
3. Use your A/B cable to connect your board to your computer
4. Open and CoolTerm
5. Connect to your serial port should look something like COM3 or USB 1121

6. Set the baudrate to 115200

7. Select the Terminal tab and make sure your the line Mode option is selected under Terminal mode 

GCODE commands OT-One S

Power On: (must do this first after Smoothie is powered on)




Halt: M112

Refresh: M999

Get Switches: (the endstop values)


Homing: (both G28.2 and G28.3 must be sent)

G28.2   G28.3                                      # home all axis

G28.2X   G28.3X                                 # home X axis

G28.2AB   G28.3AB                            # home AB axis

Set Axis Max Speed:
(each axis will not go above that mm/sec speed)

M203.1 X250 Y250  Z66 A16 B16       # in mm/sec, not mm/minute!! (for example, 250mm/sec = 15,000mm/min)

Set Move Speed: (in mm/minute, but if axis max speed is lower it will use the max speed)

G0 F15000                                           # Set speed to 15,000 mm/min

G0 F5000                                             # Set speed to 5,000 mm/min


G90                                                     # set to absolute movements

G0 X100                                              # move X to 100mm

G91                                                     # set to relative movements

G0 X20                                                # move X 20mm relatively (arrives at 120mm)

G90                                                     # set to absolute movements

G0 X10 Y10 Z10 A10 B10                  # move all axis at the same time

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