> For the complete documentation index, see [llms.txt](https://yams.yassrobotics.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://yams.yassrobotics.com/api-reference/java-reference/config/arm-config.md).

# ArmConfig

**Package:** `yams.mechanisms.config`

`ArmConfig` configures a single-jointed arm mechanism. All builder methods return the `ArmConfig` instance for chaining.

See also: [Arm](/api-reference/java-reference/mechanisms/arm.md)

***

## Constructor

```java
ArmConfig()
ArmConfig clone()  // Deep copy
```

***

## Builder Methods

> **Required for simulation:** `withLength()` must be set for `SingleJointedArmSim` to work correctly. All other methods are optional.

| Method                                                        | Parameters                                                | Description                                                                                                                                                      |
| ------------------------------------------------------------- | --------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `withLength(Distance distance)`                               | `distance`: arm link length                               | **Required for simulation.** Sets the physical length of the arm link. Used by `SingleJointedArmSim`. Without this, the physics simulation cannot model the arm. |
| `withHardLimits(Angle min, Angle max)`                        | `min`: lower bound, `max`: upper bound                    | Sets the physical rotation limits. The motor controller will not command positions outside these angles. Optional.                                               |
| `withTelemetry(String name, TelemetryVerbosity verbosity)`    | `name`: NT key prefix, `verbosity`: `LOW`/`MEDIUM`/`HIGH` | Enables NetworkTables telemetry for this mechanism. Optional.                                                                                                    |
| `withSimColor(Color8Bit color)`                               | `color`: RGB color                                        | Sets the Mechanism2d visualization color. Defaults to a built-in color if not set. Optional.                                                                     |
| `withMechanismPositionConfig(MechanismPositionConfig config)` | `config`: position config                                 | Configures the visualization plane and 3D offset for this mechanism. Optional.                                                                                   |

***

## Getters

| Method                         | Returns                        | Description                                                                        |
| ------------------------------ | ------------------------------ | ---------------------------------------------------------------------------------- |
| `getTelemetryName()`           | `Optional<String>`             | The configured NT prefix, or empty if telemetry is not set.                        |
| `getTelemetryVerbosity()`      | `Optional<TelemetryVerbosity>` | The configured verbosity, or empty.                                                |
| `getLength()`                  | `Optional<Distance>`           | The arm length, or empty if not configured.                                        |
| `getLowerHardLimit()`          | `Optional<Angle>`              | Lower hard limit angle, or empty.                                                  |
| `getUpperHardLimit()`          | `Optional<Angle>`              | Upper hard limit angle, or empty.                                                  |
| `getSimColor()`                | `Color8Bit`                    | The visualization color. Always returns a value; falls back to a built-in default. |
| `getMechanismPositionConfig()` | `MechanismPositionConfig`      | The position/plane configuration.                                                  |

***

## Example

```java
ArmConfig config = new ArmConfig()
    .withLength(Meters.of(0.6))
    .withHardLimits(Degrees.of(-90), Degrees.of(90))
    .withTelemetry("Arm", TelemetryVerbosity.HIGH);
```