Skip to main content
Before using your motor with OSSM, you must program it to set the correct steps per revolution and communication parameters.
Motors purchased from Research and Desire come pre-programmed. You only need to follow this guide if you sourced your motor elsewhere.

​
Web-Based Programming Tool

The easiest way to program your Gold Motor is the browser-based tool:

Gold Motor Programming Tool

Program your motor directly from Chrome, Edge, or other Chromium-based browsers using the Web Serial API.

​
Prerequisites

Before you begin, gather the following:
  • RS485 to USB adapter with 5V+, GND, A, and B pins (example adapter)
  • 20-36V DC power supply for the motor
  • Chromium-based browser (Chrome, Edge, Brave, etc.)

​
Programming Instructions

1

Disconnect the signal cable

Remove the OSSM Reference Board 4-pin signal plug from the motor.
The signal cable must be disconnected during programming. Leaving it connected can cause communication conflicts and programming failures.
2

Connect the RS485 adapter

Wire the RS485 USB adapter to the motor programming port:
Adapter PinMotor Pin
AA
BB
5V+5V+
GNDGND
If you don’t have the matching plug for the AIM series motor programming port, you can use individual jumper wires to make the connections.
3

Power the motor

Supply 20-36V DC power to the motor through either:
  • The OSSM Reference Board
  • An external power supply
Verify the green LED on the rear of the servo illuminates, confirming power is connected.
4

Connect to the programming tool

  1. Open the Gold Motor Programming Tool in your browser
  2. Click Connect to Motor
  3. Select your USB serial port from the browser dialog
The tool reads and displays the current motor settings.
5

Configure motor settings

Review and adjust the settings as needed:
  • Basic settings are displayed by default and are sufficient for most OSSM builds
  • Advanced settings can be revealed but require caution
Incorrect advanced settings can make the motor unusable. Only modify advanced settings if you understand their function.
6

Write settings to motor

  1. Click Write Settings to program the motor
  2. The tool writes settings multiple times to ensure reliability
  3. Verify the updated values display correctly
Confirm all settings match your expected configuration before proceeding.
7

Disconnect and reassemble

  1. Remove power from the motor
  2. Disconnect the RS485 programming adapter
  3. Reconnect the OSSM signal cable

​
Running the Tool Locally

You can run the programming tool offline:
  1. Download the GMP folder from the OSSM hardware repository
  2. Open index.html in a Chromium-based browser
  3. Follow the same connection and programming steps

​
Troubleshooting

  • Verify the RS485 adapter is properly connected
  • Check that A connects to A and B connects to B (not crossed)
  • Ensure the motor has power (green LED visible)
  • Try a different USB port
  • Confirm your browser supports Web Serial API
  • Disconnect and reconnect the RS485 adapter
  • Power cycle the motor
  • Ensure the OSSM signal cable is disconnected
  • Try reducing the distance between adapter and motor
  • Re-run the write operation
  • Verify the tool shows success after writing
  • Check for firmware compatibility issues

​
Legacy Python Script

A Python-based programming script is available for advanced users who prefer command-line tools. This script is less maintained than the web tool.
The Python script writes default settings to the Gold Motor and displays current configuration. Find it in the OSSM hardware repository.

​
Default Settings Changed

The programming tools configure these essential settings:
SettingValuePurpose
Steps per revolution800Required for OSSM motion control
Communication protocolRS485Matches OSSM PCB interface
Over-torque behaviorReduce torquePrevents sudden motor disable