Sound Servo (PC Speaker)

1. Level Value

This is the detected audio loudness coming from your PC’s speaker output. When sound gets louder, this value should increase. If you play audio and this number never changes, ARC is not “hearing” your PC output.

2. Servo Position

This shows the current servo position being sent (between your configured Minimum and Maximum positions). The skill calculates this position by taking the Level Value and multiplying it by the Scalar, then mapping the result into your Min/Max range.

3. Pause Checkbox

When checked, audio capture is paused and the servo will stop reacting to sound changes. Use this to temporarily “freeze” movement while you adjust settings.

4. Audio Waveform

A visual display of your PC’s audio output. If you see the waveform moving, the skill is receiving audio. If it is flat while sound is playing, check your Windows output device/volume.

1. Title Field

The name of this skill instance as it appears in ARC. You can rename it to something descriptive like Mouth Sound Servo.
Note: If you use controlCommand() in scripts, renaming changes the title you must reference.

2. Board Index Drop-down

Select which connected controller board the servo is on (for example: EZ-B v4 #0, #1, etc.). If you have only one board connected, this is usually 0.

3. Update Speed Drop-down

How often (in milliseconds) the skill samples the audio level and updates the servo.
Lower number = faster response (smoother/faster mouth movement) but more frequent updates.
Higher number = slower response (less movement, more lag). The range is 100 to 60000, and the default is 100 ms.

4. Port Drop-down

Choose the digital port where your servo signal wire is connected (for example D0, D1, etc.). If the wrong port is selected, the servo won’t move (or a different servo may move).

5. Scalar Drop-down

The multiplier that increases or decreases how strongly the servo reacts to sound. Range: 0.25 to 9.75 (default 1.5).

• If the servo barely moves: increase the Scalar.
• If the servo “slams” to the ends too easily: decrease the Scalar.

6. Minimum Position Adjust

Sets the servo position used for the “quiet” end of the movement (the lowest audio levels).
Left-click to adjust using the control. Right-click to type a number.
Example for a mouth: Min might be the “mouth closed” position.

7. Maximum Position Adjust

Sets the servo position used for the “loud” end of the movement (the highest audio levels).
Left-click to adjust using the control. Right-click to type a number.
Example for a mouth: Max might be the “mouth open” position.

8. Multi Servo Edit Window

Lets you select additional servos that will mirror the movement of the “master” servo. This is useful if you want multiple parts to move together (for example: two jaw servos, or a mouth plus cheeks).
Tip: If you need servos to move differently (not mirrored), add multiple instances of this skill and configure each one separately.

9. Invert Direction Checkbox

Reverses the direction of the servo movement. Use this if the servo moves opposite of what you expect (for example, it closes when it should open).
Example: If 180 normally moves left, with invert enabled 180 will move right.

10. Variable Field

The ARC variable name that will store the detected audio output level. This allows you to use the sound level in scripts or other skills (for example, display it, log it, or trigger actions when it exceeds a value).