docs: document MA-USB8 beam direction mapping

docs/hardware/en/modules/micarray_usbboard_bl616.md

@@ -20,6 +20,27 @@ The UAC channels are defined as follows:
 
 All channels use a 48 kHz sample rate. During UAC streaming, the raw PEC data for CH6 is replaced by the beamformed result.
 
+### Beam direction and physical microphone order
+
+View the front of the microphone array with its connector and flat edge at the bottom. MIC0 (CH0) is at the top; MIC1–MIC5 (CH1–CH5) continue clockwise around the outer ring. Serial commands `0,1,..9,A,B` start at MIC0 and select the beam direction clockwise in 30° steps:
+
+| Command | Angle | Physical direction |
+| --- | --- | --- |
+| `0` | 0° | MIC0 / CH0 |
+| `1` | 30° | Between MIC0 and MIC1 |
+| `2` | 60° | MIC1 / CH1 |
+| `3` | 90° | Between MIC1 and MIC2 |
+| `4` | 120° | MIC2 / CH2 |
+| `5` | 150° | Between MIC2 and MIC3 |
+| `6` | 180° | MIC3 / CH3 |
+| `7` | 210° | Between MIC3 and MIC4 |
+| `8` | 240° | MIC4 / CH4 |
+| `9` | 270° | Between MIC4 and MIC5 |
+| `A` | 300° | MIC5 / CH5 |
+| `B` | 330° | Between MIC5 and MIC0 |
+
+See the placement drawing in the [microphone array module guide](./micarray.md) for the physical numbering. CH6 is the beamformed output; it does not represent a seventh physical direction.
+
 > This document is a user guide for MA-USB8. It covers connection, device verification, audio capture, beamforming, how to read/parse hotmap frames, and common troubleshooting.
 
 ## Quick start
@@ -226,7 +247,7 @@ Total packet length = 16 + 256 = 272 bytes. The header is used for frame alignme
 
 | Command | Input (Lower/Uppercase: Off/On) | Default | Remarks | Input Source |
 | ------- | ------------------------------ | ------- | ------- | ------------ |
-| Set UAC CH6 beam direction | 0..9, A, B | 0 | angle = value × 30° (0..B → 0°,30°,…330°). Corresponds to the clockwise direction starting from microphone 0 as per the [microphone array](./micarray.md). | Any (serial/CDC) |
+| Set UAC CH6 beam direction | 0..9, A, B | 0 | Selects clockwise in 30° steps from MIC0 / CH0; see [Beam direction and physical microphone order](#Beam-direction-and-physical-microphone-order). CH6 carries the beamformed output. | Any (serial/CDC) |
 | Adjust source localization activation threshold | t/T | 650 | t: decrease by 50; T: increase by 50; adjustable range: 0–2000 | Any (serial/CDC) |
 | UART sound-map pseudocolor toggle | c/C | c | Requires ASCII 16×16 printing enabled | UART only |
 | UART internal debug info toggle | d/D | d | Enables/disables debug output | UART only |

docs/hardware/zh/modules/micarray_usbboard_bl616.md

@@ -20,6 +20,27 @@ UAC 通道定义如下：
 
 所有通道的采样率均为 48 kHz。UAC 传输期间，CH6 对应的 PEC 原始数据会被波束合成结果覆盖。
 
+### 波束方向与物理麦克风顺序
+
+观察麦克风阵列正面并将连接器、平边朝下：外圈顶部为 MIC0（CH0），MIC1～MIC5（CH1～CH5）沿顺时针排列。串口命令 `0,1,..9,A,B` 从 MIC0 方向开始，以 30° 为步进沿顺时针选择波束方向：
+
+| 命令 | 角度 | 对应物理方向 |
+| --- | --- | --- |
+| `0` | 0° | MIC0 / CH0 |
+| `1` | 30° | MIC0 与 MIC1 之间 |
+| `2` | 60° | MIC1 / CH1 |
+| `3` | 90° | MIC1 与 MIC2 之间 |
+| `4` | 120° | MIC2 / CH2 |
+| `5` | 150° | MIC2 与 MIC3 之间 |
+| `6` | 180° | MIC3 / CH3 |
+| `7` | 210° | MIC3 与 MIC4 之间 |
+| `8` | 240° | MIC4 / CH4 |
+| `9` | 270° | MIC4 与 MIC5 之间 |
+| `A` | 300° | MIC5 / CH5 |
+| `B` | 330° | MIC5 与 MIC0 之间 |
+
+物理编号和板上位置可参见[麦克风阵列模块](./micarray.md)的点位图。CH6 是波束合成输出，不代表第 7 个物理方向。
+
 > 本文是 MA-USB8 的使用指南，覆盖从接线、验证设备、音频录制、波束成形到如何读取/解析声场热力图与常见故障排查。
 
 ## 快速上手
@@ -226,7 +247,7 @@ SUBSYSTEM=="tty", ATTRS{idVendor}=="359F", MODE="0666", GROUP="plugdev"
 ### 完整指令表（开发者）
 | 指令 | 输入(小/大写: 关/开) | 默认值 | 作用 | 输入源 |
 | - | - | - | - | - |
-| 设置 UAC CH6 波束成型方向角度 | 0,1,..9,A,B | 0 | 将波束指向以 30° 步进的方向（实际角度 = 输入 × 30）；CH6 会输出合成后的音频 | 任意（串口/CDC） |
+| 设置 UAC CH6 波束成型方向角度 | 0,1,..9,A,B | 0 | 从 MIC0 / CH0 开始顺时针选择方向，每步 30°；映射见[波束方向与物理麦克风顺序](#波束方向与物理麦克风顺序)，CH6 输出合成音频 | 任意（串口/CDC） |
 | 修改声源定位激活阈值(t,T) | t, T | 650 | t: -50, T: +50, 阈值可调范围: 0~2000 | 任意（串口/CDC） |
 | UART 声源定位图伪彩映射开关 (c/C) | c, C | c | 打开/关闭热力图伪彩（color map），需要先开启 16×16 打印 | 仅 UART |
 | UART 打印内部调试信息 (d/D) | d, D | d | 启用/禁用调试信息输出 | 仅 UART |