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Program your Gold Motor (AIM series) for OSSM before first use. You will set steps per revolution and the communication parameters used by the OSSM Reference Board.
Motors purchased from Research and Desire come pre-programmed. Only follow this guide if you sourced your motor elsewhere or need to restore defaults.

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Web-based programming tool

Use the browser tool to read and write motor settings. Open Gold Motor Programming Tool
  • The Web Serial API is supported in Chromium-based browsers on Windows, macOS, and Linux. It is not available in Safari or Firefox.
  • Some USB–RS485 adapters require drivers (e.g., FTDI/CP210x/CH340). Install the vendor driver if your adapter is not detected by the OS.

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Prerequisites

Gather the following before you start:
  • RS485 to USB adapter with 5V+, GND, A, and B pins (for example, a terminal-block style adapter)
  • 20–36 V DC power supply for the motor
  • Chromium-based desktop browser (Chrome, Edge, Brave, etc.)
  • Access to the OSSM Reference Board (for power and the signal cable you will temporarily disconnect)
Never power the motor from USB alone. The motor must have its normal 20–36 V DC input during programming.

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Programming instructions

1

Disconnect the signal cable

Remove the OSSM Reference Board 4‑pin signal plug from the motor.
Leave the signal cable disconnected during programming. Having both the RS485 adapter and the OSSM board connected can cause bus conflicts and failed writes.
2

Connect the RS485 adapter

Wire the RS485 USB adapter to the motor programming port:
Adapter pinMotor pin
AA
BB
5V+5V+
GNDGND
Adapter labeling is not always consistent. If the tool cannot detect the motor, swap A and B on the adapter and try again.
3

Power the motor

Provide 20–36 V DC to the motor using either:
  • The OSSM Reference Board (recommended for convenience), or
  • An external bench supply
Confirm the green LED on the rear of the servo is lit to verify power.
4

Open and connect the programming tool

  1. Open the Gold Motor Programming Tool in your browser.
  2. Select Connect to Motor.
  3. Choose your USB serial device from the dialog and grant access.
The tool will read and display the current motor settings.
5

Review and configure settings

Adjust only what you need for OSSM:
  • Basic settings are surfaced by default and cover the typical OSSM configuration.
  • Advanced settings are available but should be changed only if you understand their impact.
Incorrect advanced values can disable motion or make the motor appear unresponsive. Document original values before changing them.
6

Write settings and verify

  1. Select Write Settings.
  2. Wait for the write sequence to complete. The tool writes critical values multiple times for reliability.
  3. Power‑cycle the motor, reconnect, and select Read Settings to confirm persistence.
All values should match your expected configuration after the power cycle.
7

Disconnect and reassemble

  1. Remove power from the motor.
  2. Unplug the RS485 programming adapter.
  3. Reconnect the OSSM 4‑pin signal cable.
  4. Restore normal power and proceed with OSSM setup.

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Default settings applied by the tool

The programming tools set the required OSSM defaults:
SettingValuePurpose
Steps per revolution800Ensures correct motion scaling in OSSM
Communication protocolRS485Matches the OSSM PCB interface
Over‑torque behaviorReduce torquePrevents abrupt motor disable under load
Depending on your motor and adapter, the tool may also configure bus parameters (baud rate and device address) to OSSM defaults. Use the Read Settings function to confirm.

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Run the tool locally (offline)

You can use the tool offline if your environment blocks external sites.
1

Get the tool files

Download the GMP folder from the OSSM hardware repository and keep the folder structure intact on your computer.
2

Open the tool

Open index.html from the GMP folder in a Chromium-based browser.
3

Program as usual

Follow the same connection and programming steps described above.
Some browsers restrict file:// access to serial ports via Web Serial on managed devices. If you encounter an error, serve the folder over http:// using a simple local server (for example, python -m http.server) and open the page from http://localhost.

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Troubleshooting

  • Confirm the RS485 adapter has power (some adapters require 5V from the motor’s programming header).
  • Verify A connects to A and B connects to B. If labels are unclear, try swapping A/B at the adapter.
  • Ensure the motor is powered and the green LED is on.
  • Try a different USB port or cable.
  • Install or update the USB–serial driver for your adapter chipset.
  • Use a supported Chromium-based browser and grant serial permission when prompted.
  • Disconnect and reconnect the RS485 adapter, then retry.
  • Power-cycle the motor and reconnect in the tool.
  • Ensure the OSSM signal cable is disconnected during programming.
  • Shorten the RS485 wiring run and avoid loose jumper connections.
  • Remove other RS485 devices from the bus so only the motor and adapter are connected.
  • Run Write Settings again and wait for confirmation.
  • Power-cycle the motor, then use Read Settings to verify.
  • If values still revert, check for firmware compatibility constraints and reapply defaults using the tool’s basic settings.
  • Install the correct driver for your adapter and reboot.
  • Try another USB port (avoid unpowered hubs).
  • Reduce electrical noise: route RS485 lines away from motor power leads.

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Legacy Python script

A command‑line Python script exists for advanced users. It is less maintained than the web tool and is intended for recovery or automation scenarios.
The script writes OSSM default settings and prints the current configuration. You can find it in the OSSM hardware repository under the Gold Motor tools.
Test with the web tool first. Use the Python script only if you need headless or automated configuration.

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Safety and best practices

  • Work with power removed whenever changing wiring.
  • Do not short 5V+ to GND on the programming header.
  • Keep RS485 leads short and firmly terminated. For long runs, a 120 Ω terminator may improve signal integrity.
  • Record original values before making changes, and save a screenshot of the final configuration for future reference.
After successful programming and reconnection to OSSM, jog the motor in your control software to verify direction, scaling, and smooth motion.