Configure a Fake Motor

Configuring a fake motor can be convenient for testing software without using any hardware. For example, you can use a fake component as a placeholder while waiting on a hardware shipment, so that other components that depend on this motor (for example, a base) won’t fail to initialize, and your control code won’t throw errors when it fails to find a physical motor connected to your machine.

{
  "components": [
    {
      "name": "<your-motor-name>",
      "model": "fake",
      "type": "motor",
      "namespace": "rdk",
      "attributes": {
        <...>
      },
      "depends_on": []
    }
  ]
}

{
  "components": [
    {
      "name": "fake-motor",
      "model": "fake",
      "type": "motor",
      "namespace": "rdk",
      "attributes": {
        "pins": {
          "dir": "",
          "pwm": ""
        },
        "board": "",
        "dir_flip": false
      },
      "depends_on": []
    }
  ]
}

Since a fake motor isn’t a physical piece of hardware, attributes are only representational and not required. However, if you would like to mock up a virtual placeholder for a real, physical motor, you can configure some or all of the following attributes:

Nested within pins:

Pin Information

There are three common ways for the computing device to communicate with a brushed DC motor driver chip. The driver data sheet (for a real, not fake, motor) will specify which one to use.

• PWM/DIR: One digital input (such as a GPIO pin) sends a pulse width modulation (PWM) signal to the driver to control speed while another digital input sends a high or low signal to control the direction.
• In1/In2 (or A/B): One digital input is set to high and another set to low turns the motor in one direction and vice versa, while speed is controlled with PWM through one or both pins.
• In1/In2 + PWM: Three pins: an In1 (A) and In2 (B) to control direction and a separate PWM pin to control speed.

Test the motor

Once your motor is configured and your machine is connected, go to the CONTROL tab and click on the motor’s dropdown panel. Use the buttons to try turning your motor forwards or backwards at different power levels and notice how the Position number changes.

Troubleshooting

If your motor is not working as expected, follow these steps:

1. Check your machine logs on the LOGS tab to check for errors.
2. Review this motor model’s documentation to ensure you have configured all required attributes.
3. Check that all wires are securely attached to the correct pins.
4. Click on the TEST panel on the CONFIGURE or CONTROL tab and test if you can use the motor there.

If none of these steps work, reach out to us on the Community Discord and we will be happy to help.

Next steps

For more configuration and usage info, see: