{% hint style="danger" %}
A servo plug has three wires. Plug it in the right direction or you may burn the chip. The color of wires may vary for different models. However, the darkest-colored (Black or Brown) wire (GND for ground) is always the GND wire as a convention. The GND wire should be plugged closest to the board.
{% endhint %}
{% hint style="danger" %}
The index number of the joint servo has **no corresponding relationship** with the PWM pin number on the main board. **You don't even need to read the pin numbers on the PCB board.**
{% endhint %}
---
# Agent Instructions: Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
GET https://guide.petoi.com/quick-reference/petoi-robot-joint-index/joint-pins-on-nyboard/bittle.md?ask=
```
The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.