diff --git a/README.md b/README.md
index f90bbad..b33ff76 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,8 @@
 # ch934x_serial
 
 Flutter 插件:封装南京沁恒微电子 **CH934X 系列** USB 转多串口芯片的
-Android SDK,提供设备查找、串口读写、GPIO 与 Modem 控制等能力。
+Android SDK,提供设备枚举、串口读写、GPIO/Modem 控制、Break 信号、
+串口参数配置、设备状态查询等完整能力。
 
 ## 文档
 
@@ -26,5 +27,5 @@ final devices = await plugin.getDeviceList();
 
 ## 平台支持
 
-- ✅ Android(基于 `CH934XLib.jar` 反射桥接)
+- ✅ Android(基于 `CH934XLib.jar`)
 - ❌ iOS / Web / Desktop(暂未实现)
diff --git a/android/src/main/java/com/xiarui/ch934x_serial/Ch934xSerialPlugin.java b/android/src/main/java/com/xiarui/ch934x_serial/Ch934xSerialPlugin.java
index 306ba32..439024f 100644
--- a/android/src/main/java/com/xiarui/ch934x_serial/Ch934xSerialPlugin.java
+++ b/android/src/main/java/com/xiarui/ch934x_serial/Ch934xSerialPlugin.java
@@ -229,6 +229,36 @@ public class Ch934xSerialPlugin implements FlutterPlugin, MethodCallHandler, Act
                     exceptionCallbackEnabled = true;
                     result.success(null);
                     break;
+                case "setBreak":
+                    result.success(handleSetBreak(call));
+                    break;
+                case "getCurrentMode":
+                    result.success(handleGetCurrentMode(call));
+                    break;
+                case "getGPIOCount":
+                    result.success(handleGetGPIOCount(call));
+                    break;
+                case "getGPIOGroup":
+                    result.success(handleGetGPIOGroup(call));
+                    break;
+                case "enableGPIO":
+                    result.success(handleEnableGPIO(call));
+                    break;
+                case "setGPIODir":
+                    result.success(handleSetGPIODir(call));
+                    break;
+                case "queryGPIODirFromCache":
+                    result.success(handleQueryGPIODirFromCache(call));
+                    break;
+                case "isConnected":
+                    result.success(handleIsConnected(call));
+                    break;
+                case "getConnectedDevices":
+                    result.success(handleGetConnectedDevices());
+                    break;
+                case "setSerialParameter":
+                    result.success(handleSetSerialParameter(call));
+                    break;
                 default:
                     result.notImplemented();
             }
@@ -637,6 +667,187 @@ public class Ch934xSerialPlugin implements FlutterPlugin, MethodCallHandler, Act
         return modemStatusCache;
     }
 
+    // ------------------------------------------------------------------------
+    // 新增接口(对应文档 setBreak / querySerialErrorCount / getCurrentMode / …)
+    // ------------------------------------------------------------------------
+
+    /** 文档 setBreak。 */
+    private boolean handleSetBreak(@NonNull MethodCall call) {
+        if (activeDevice == null || activeSerialNumber < 0) {
+            return false;
+        }
+        Boolean valid = call.argument("valid");
+        if (valid == null) {
+            return false;
+        }
+        try {
+            return CH934XManager.getInstance().setBreak(
+                    activeDevice, activeSerialNumber, valid);
+        } catch (Throwable t) {
+            return false;
+        }
+    }
+
+    /** 文档 getCurrentMode。 */
+    private int handleGetCurrentMode(@NonNull MethodCall call) {
+        if (activeDevice == null || activeSerialNumber < 0) {
+            return -1;
+        }
+        try {
+            Mode mode = CH934XManager.getInstance().getCurrentMode(
+                    activeDevice, activeSerialNumber);
+            if (mode == null) return -1;
+            String name = mode.name();
+            if ("NORMAL".equals(name)) return 0;
+            if ("HARDFLOW".equals(name)) return 1;
+            if ("GPIO".equals(name)) return 2;
+            return -1;
+        } catch (Throwable t) {
+            return -1;
+        }
+    }
+
+    /** 文档 getGPIOCount。 */
+    private int handleGetGPIOCount(@NonNull MethodCall call) {
+        UsbDevice device = resolveDevice(call);
+        if (device == null) {
+            return -1;
+        }
+        try {
+            return CH934XManager.getInstance().getGPIOCount(device);
+        } catch (Throwable t) {
+            return -1;
+        }
+    }
+
+    /** 文档 getGPIOGroup。 */
+    private int handleGetGPIOGroup(@NonNull MethodCall call) {
+        UsbDevice device = resolveDevice(call);
+        if (device == null) {
+            return -1;
+        }
+        try {
+            return CH934XManager.getInstance().getGPIOGroup(device);
+        } catch (Throwable t) {
+            return -1;
+        }
+    }
+
+    /** 文档 enableGPIO。需要 ChipType 参数,由 Dart 侧传入 int 映射值。 */
+    private boolean handleEnableGPIO(@NonNull MethodCall call) {
+        UsbDevice device = resolveDevice(call);
+        if (device == null) {
+            return false;
+        }
+        Integer chipTypeVal = call.argument("chipType");
+        Integer gpioGroup = call.argument("gpioGroup");
+        Integer enable = call.argument("enable");
+        if (chipTypeVal == null || gpioGroup == null || enable == null) {
+            return false;
+        }
+        ChipType chipType = parseChipType(chipTypeVal);
+        if (chipType == null) {
+            return false;
+        }
+        try {
+            return CH934XManager.getInstance().enableGPIO(
+                    device, chipType, gpioGroup, enable);
+        } catch (Throwable t) {
+            return false;
+        }
+    }
+
+    /** 文档 setGPIODir。 */
+    private boolean handleSetGPIODir(@NonNull MethodCall call) {
+        if (activeDevice == null) {
+            return false;
+        }
+        Integer gpioGroup = call.argument("gpioGroup");
+        Integer gpioNumber = call.argument("gpioNumber");
+        Integer dir = call.argument("dir");
+        if (gpioGroup == null || gpioNumber == null || dir == null) {
+            return false;
+        }
+        GPIO_DIR gpioDir = dir == 0 ? GPIO_DIR.IN : GPIO_DIR.OUT;
+        try {
+            return CH934XManager.getInstance().setGPIODir(
+                    activeDevice, gpioGroup, gpioNumber, gpioDir);
+        } catch (Throwable t) {
+            return false;
+        }
+    }
+
+    /** 文档 queryGPIODirFromCache。返回 0=IN,1=OUT,负值=失败。 */
+    private int handleQueryGPIODirFromCache(@NonNull MethodCall call) {
+        if (activeDevice == null) {
+            return -1;
+        }
+        Integer gpioGroup = call.argument("gpioGroup");
+        Integer gpioNumber = call.argument("gpioNumber");
+        if (gpioGroup == null || gpioNumber == null) {
+            return -1;
+        }
+        try {
+            GPIO_DIR dir = CH934XManager.getInstance().queryGPIODirFromCache(
+                    activeDevice, gpioGroup, gpioNumber);
+            if (dir == null) return -1;
+            return dir == GPIO_DIR.OUT ? 1 : 0;
+        } catch (Throwable t) {
+            return -1;
+        }
+    }
+
+    /** 文档 isConnected。 */
+    private boolean handleIsConnected(@NonNull MethodCall call) {
+        UsbDevice device = resolveDevice(call);
+        if (device == null) {
+            return false;
+        }
+        try {
+            return CH934XManager.getInstance().isConnected(device);
+        } catch (Throwable t) {
+            return false;
+        }
+    }
+
+    /** 文档 getConnectedDevices。返回已打开设备的 deviceId 列表。 */
+    private List<Integer> handleGetConnectedDevices() {
+        List<Integer> ids = new ArrayList<>();
+        try {
+            ArrayList<UsbDevice> devices = CH934XManager.getInstance().getConnectedDevices();
+            if (devices != null) {
+                for (UsbDevice d : devices) {
+                    ids.add(d.getDeviceId());
+                }
+            }
+        } catch (Throwable ignored) {
+        }
+        return ids;
+    }
+
+    /** 文档 setSerialParameter。配置当前活跃串口的参数。 */
+    private boolean handleSetSerialParameter(@NonNull MethodCall call) {
+        if (activeDevice == null || activeSerialNumber < 0) {
+            return false;
+        }
+        Integer baud = call.argument("baud");
+        Integer dataBit = call.argument("dataBit");
+        Integer stopBit = call.argument("stopBit");
+        Integer parityBit = call.argument("parityBit");
+        Boolean flow = call.argument("flow");
+        if (baud == null || dataBit == null || stopBit == null
+                || parityBit == null || flow == null) {
+            return false;
+        }
+        try {
+            return CH934XManager.getInstance().setSerialParameter(
+                    activeDevice, activeSerialNumber,
+                    baud, dataBit, stopBit, parityBit, flow);
+        } catch (Throwable t) {
+            return false;
+        }
+    }
+
     // ------------------------------------------------------------------------
     // 内部辅助
     // ------------------------------------------------------------------------
@@ -680,6 +891,25 @@ public class Ch934xSerialPlugin implements FlutterPlugin, MethodCallHandler, Act
         return 5;
     }
 
+    /** 将 Dart 侧传入的 int 还原为 SDK ChipType。null 表示未知类型。 */
+    @Nullable
+    private ChipType parseChipType(int value) {
+        String name;
+        switch (value) {
+            case 0:  name = "CH9344"; break;
+            case 1:  name = "CH9344L"; break;
+            case 2:  name = "CH9350"; break;
+            case 3:  name = "CH9348Q"; break;
+            case 4:  name = "CH9342"; break;
+            default: return null;
+        }
+        try {
+            return ChipType.valueOf(name);
+        } catch (IllegalArgumentException e) {
+            return null;
+        }
+    }
+
     private List<Map<String, Object>> buildSerialPortList(int count) {
         List<Map<String, Object>> ports = new ArrayList<>();
         for (int i = 0; i < Math.max(count, 0); i++) {
diff --git a/docs/CH934X_Plugin_使用说明.md b/docs/CH934X_Plugin_使用说明.md
index 077f996..f360c29 100644
--- a/docs/CH934X_Plugin_使用说明.md
+++ b/docs/CH934X_Plugin_使用说明.md
@@ -16,9 +16,13 @@ Android SDK 封装的 Flutter 插件,文档面向其他 Flutter 开发者,介绍
   - CH934X 设备枚举、序列号读取、芯片类型识别
   - 多串口打开 / 关闭 / **同设备内串口切换**
   - 字节级串口读写
-  - GPIO 输出 / 输入
+  - GPIO 输出 / 输入 / 方向控制 / 使能
   - Modem 控制 (DTR/RTS) 与状态 (CTS/DSR/RI/DCD) 读取
   - **主动申请 USB 权限**
+  - **Break 信号控制**
+  - **串口参数配置(波特率/数据位/停止位/校验/流控)**
+  - **查询设备连接状态与已打开设备列表**
+  - **查询 GPIO 数量、组信息**
   - 设备拔出、Modem 错误等异常事件回调
 - **底层依赖:** 沁恒官方 `CH934XLib.jar`(插件随包发布,位于
   `android/libs/CH934XLib.jar`),通过原生 `CH934XManager` 单例直接调用,
@@ -189,14 +193,40 @@ await sub.cancel();
 ### 3.4 GPIO 接口
 
 ```dart
+// 设置 GPIO 输出电平
 final ok = await plugin.setGpioOutput(gpioNumber: 0, level: 1);
-final value = await plugin.getGpioInput(0); // 负值表示失败
+
+// 读取 GPIO 输入电平(负值表示失败)
+final value = await plugin.getGpioInput(0);
 ```
 
 - `gpioNumber` 与 `level` 与原文档保持一致(0/1)。
 - `getGpioInput` 失败时返回 -1,业务方需要自行处理。
 - GPIO 操作同样作用于**当前活跃串口**。
 
+### 3.4.1 GPIO 方向控制
+
+```dart
+// 使能 GPIO(需要先获取 chipType,可从 Ch934xDeviceInfo.deviceType 取得)
+await plugin.enableGpio(chipType: device.deviceType, gpioGroup: 0, enable: 1);
+
+// 设置 GPIO 方向
+await plugin.setGpioDir(gpioGroup: 0, gpioNumber: 0, dir: GpioDirection.out);
+
+// 从缓存查询 GPIO 方向
+final dir = await plugin.queryGpioDirFromCache(gpioGroup: 0, gpioNumber: 0);
+if (dir == GpioDirection.out) { /* 输出 */ }
+
+// 查询 GPIO 数量与组数
+final count = await plugin.getGpiocount(device.deviceId);
+final groups = await plugin.getGpiogroup(device.deviceId);
+```
+
+- `GpioDirection` 常量: `in_ = 0`(输入)、`out = 1`(输出)。
+- `enableGpio` 的 `enable` 参数: CH9344 传 1/0 控制整组;CH348 使用位掩码。
+- 方向查询返回 -1 表示失败。
+- `getGpiocount`/`getGpiogroup` 失败时返回 -1,需先 `openPort`。
+
 ### 3.5 Modem 控制接口
 
 ```dart
@@ -224,6 +254,78 @@ final sub = await plugin.setExceptionCallback((event) {
 await sub.cancel();
 ```
 
+- 异常类型见 `Ch934xExceptionType`:
+  - `deviceDetached = 1`:设备被拔出(由 SDK 的 `usbDeviceDetach` 触发)。
+  - `ioError = 2`:Modem overrun / parity / frame 等错误。
+  - `sdk = 3`:原生 SDK 主动抛出的其他异常(目前未触发,保留语义)。
+  - `unknown = 0`:未识别(当前未触发,保留语义)。
+- `Ch934xException` 包含 `type / message / cause`,`toString()` 会把
+  `type` 翻译为对应的常量名,方便日志/UI 显示。
+- 返回的 `StreamSubscription` **必须在合适时机 `cancel`**,以便
+  释放底层 `StreamController` 与 `MethodCallHandler`。
+
+### 3.7 其他接口
+
+#### 3.7.1 Break 信号
+
+```dart
+final ok = await plugin.setBreak(true); // 设置 Break(低电平有效)
+```
+
+- 作用于**当前活跃串口**。
+
+#### 3.7.2 获取当前串口模式
+
+```dart
+final mode = await plugin.getCurrentMode();
+// mode 取值见 Ch934xMode 常量
+```
+
+- `Ch934xMode` 常量: `normal = 0`(普通)、`hardflow = 1`(硬件流控)、`gpio = 2`(GPIO)。
+- **仅对 CH934X 型号有效**,CH348 返回 -1。
+
+#### 3.7.3 设备连接状态
+
+```dart
+final connected = await plugin.isConnected(device.deviceId);
+final ids = await plugin.getConnectedDevices();
+```
+
+- `isConnected`: 查询指定设备是否已被打开。
+- `getConnectedDevices`: 返回当前已打开设备的 `deviceId` 列表。
+
+### 3.8 串口参数配置
+
+```dart
+// 配置波特率为 9600
+final ok = await plugin.setSerialParameter(
+  baud: 9600,
+  dataBit: 8,
+  stopBit: 1,
+  parityBit: 0,
+  flow: false,
+);
+```
+
+- 作用于**当前活跃串口**。`openPort` 内部默认设为 `115200/8/1/N/无流控`,
+  如需修改可在此之后调用。
+- `stopBit`: 0=1 停止位,1=1.5 停止位,2=2 停止位。
+- `parityBit`: 0=无校验,1=奇校验,2=偶校验。
+
+---
+
+## 4. 完整示例
+
+```dart
+final sub = await plugin.setExceptionCallback((event) {
+  debugPrint('设备异常: ${event.type} ${event.message}');
+  // 业务方应主动关闭串口、刷新设备列表或提示用户重新插拔
+});
+
+// 主动取消监听
+await sub.cancel();
+```
+
 - 异常类型见 `Ch934xExceptionType`:
   - `deviceDetached = 1`:设备被拔出(由 SDK 的 `usbDeviceDetach` 触发)。
   - `ioError = 2`:Modem overrun / parity / frame 等错误。
@@ -346,9 +448,9 @@ void main() {
   才返回真实数据,枚举阶段调用只会得到空列表。
 
 **Q3. `read()` 一直返回空数组。**
-- 确认对端设备正在发送数据,且波特率/校验位等参数与原 SDK 默认值
-  一致(`CH934XLib` 提供独立的 `setConfig` 接口,本插件当前未做
-  封装,需要时可扩展原 SDK 直接调用)。
+- 确认对端设备正在发送数据,且波特率/校验位等参数匹配。可通过
+  `setSerialParameter(baud: 9600, dataBit: 8, stopBit: 1, parityBit: 0, flow: false)`
+  配置串口参数。
 - 检查线序:RX/TX 是否接反,以及硬件流控是否正确。
 - 确认 `setActivePort` 已切换到正确的串口索引。
 
@@ -398,12 +500,23 @@ void main() {
 | `requestUsbPermission` | 2.2 增强 | 主动授权(插件新增) |
 | `read` | 6.1.1 | 串口读写 |
 | `write` | 6.2.1 | 串口读写 |
-| `setGpioOutput` | 7.1.1 | GPIO |
-| `getGpioInput` | 7.1.2 | GPIO |
+| `setSerialParameter` | setSerialParameter | 串口参数 |
+| `setBreak` | setBreak | 其他 |
+| `getCurrentMode` | getCurrentMode | 其他 |
+| `isConnected` | isConnected | 设备状态 |
+| `getConnectedDevices` | getConnectedDevices | 设备状态 |
+| `setGpioOutput` | setGPIOValue | GPIO |
+| `getGpioInput` | getGPIOValue | GPIO |
+| `setGpioDir` | setGPIODir | GPIO 方向 |
+| `queryGpioDirFromCache` | queryGPIODirFromCache | GPIO 方向 |
+| `enableGpio` | enableGPIO | GPIO |
+| `getGpiocount` | getGPIOCount | GPIO |
+| `getGpiogroup` | getGPIOGroup | GPIO |
 | `setModemControl` | 7.2.1 | Modem |
 | `getModemStatus` | 7.2.2 | Modem |
 | `setExceptionCallback` | 7.3.1 | 异常 |
 | `dataStream` | 6.1 增强 | 串口流(插件新增) |
+| `portDataStream` | 6.1 增强 | 多端口轮询流(插件新增) |
 
 ---
 
diff --git a/example/lib/main.dart b/example/lib/main.dart
index f101456..8f6dff3 100644
--- a/example/lib/main.dart
+++ b/example/lib/main.dart
@@ -378,6 +378,148 @@ class _Ch934xSerialExamplePageState extends State<Ch934xSerialExamplePage> {
                   icon: const Icon(Icons.input),
                   label: const Text('读取 GPIO0'),
                 ),
+                OutlinedButton.icon(
+                  onPressed: () async {
+                    if (!_portOpened) return;
+                    final ok = await _plugin.setBreak(true);
+                    if (!mounted) return;
+                    setState(() => _status = ok ? 'Break 已设置' : 'Break 失败');
+                  },
+                  icon: const Icon(Icons.pause),
+                  label: const Text('SetBreak'),
+                ),
+                OutlinedButton.icon(
+                  onPressed: () async {
+                    if (!_portOpened) return;
+                    final mode = await _plugin.getCurrentMode();
+                    if (!mounted) return;
+                    final label = switch (mode) {
+                      Ch934xMode.normal => '普通',
+                      Ch934xMode.hardflow => '硬件流控',
+                      Ch934xMode.gpio => 'GPIO',
+                      _ => '未知($mode)',
+                    };
+                    setState(() => _status = '当前模式: $label');
+                  },
+                  icon: const Icon(Icons.settings),
+                  label: const Text('当前模式'),
+                ),
+                OutlinedButton.icon(
+                  onPressed: () async {
+                    final device = _selectedDevice;
+                    if (device == null) {
+                      setState(() => _status = '请先选择设备');
+                      return;
+                    }
+                    final cnt = await _plugin.getGpiocount(device.deviceId);
+                    final grp = await _plugin.getGpiogroup(device.deviceId);
+                    if (!mounted) return;
+                    setState(() => _status = 'GPIO 数量=$cnt, 组数=$grp');
+                  },
+                  icon: const Icon(Icons.developer_board),
+                  label: const Text('GPIO 信息'),
+                ),
+                OutlinedButton.icon(
+                  onPressed: () async {
+                    final device = _selectedDevice;
+                    if (device == null) {
+                      setState(() => _status = '请先选择设备');
+                      return;
+                    }
+                    if (!_portOpened) {
+                      setState(() => _status = '请先打开串口');
+                      return;
+                    }
+                    final ok = await _plugin.enableGpio(
+                      chipType: device.deviceType,
+                      gpioGroup: 0,
+                      enable: 1,
+                    );
+                    if (!mounted) return;
+                    setState(() => _status = ok ? 'GPIO 已使能' : '使能 GPIO 失败');
+                  },
+                  icon: const Icon(Icons.toggle_on),
+                  label: const Text('使能GPIO'),
+                ),
+                OutlinedButton.icon(
+                  onPressed: () async {
+                    if (!_portOpened) return;
+                    final ok = await _plugin.setGpioDir(
+                      gpioGroup: 0,
+                      gpioNumber: 0,
+                      dir: GpioDirection.out,
+                    );
+                    if (!mounted) return;
+                    setState(() => _status = ok ? 'GPIO0 方向设为输出' : '设置方向失败');
+                  },
+                  icon: const Icon(Icons.swap_vert),
+                  label: const Text('GPIO方向'),
+                ),
+                OutlinedButton.icon(
+                  onPressed: () async {
+                    if (!_portOpened) return;
+                    final dir = await _plugin.queryGpioDirFromCache(
+                      gpioGroup: 0,
+                      gpioNumber: 0,
+                    );
+                    if (!mounted) return;
+                    final label = switch (dir) {
+                      GpioDirection.in_ => '输入',
+                      GpioDirection.out => '输出',
+                      _ => '未知($dir)',
+                    };
+                    setState(() => _status = 'GPIO0 方向缓存: $label');
+                  },
+                  icon: const Icon(Icons.visibility),
+                  label: const Text('查方向缓存'),
+                ),
+                OutlinedButton.icon(
+                  onPressed: () async {
+                    final device = _selectedDevice;
+                    if (device == null) {
+                      setState(() => _status = '请先选择设备');
+                      return;
+                    }
+                    final connected = await _plugin.isConnected(device.deviceId);
+                    if (!mounted) return;
+                    setState(() => _status = connected ? '设备已连接' : '设备未连接');
+                  },
+                  icon: const Icon(Icons.link),
+                  label: const Text('是否已连'),
+                ),
+                OutlinedButton.icon(
+                  onPressed: () async {
+                    final ids = await _plugin.getConnectedDevices();
+                    if (!mounted) return;
+                    setState(() => _status = '已打开设备: ${ids.isEmpty ? "无" : ids.join(", ")}');
+                  },
+                  icon: const Icon(Icons.list),
+                  label: const Text('已开设备'),
+                ),
+                OutlinedButton.icon(
+                  onPressed: () async {
+                    if (!_portOpened) return;
+                    final ok = await _plugin.setSerialParameter(
+                      baud: 9600, dataBit: 8, stopBit: 1, parityBit: 0, flow: false,
+                    );
+                    if (!mounted) return;
+                    setState(() => _status = ok ? '已设为 9600/8/1/N' : '设参失败');
+                  },
+                  icon: const Icon(Icons.tune),
+                  label: const Text('波特率9600'),
+                ),
+                OutlinedButton.icon(
+                  onPressed: () async {
+                    if (!_portOpened) return;
+                    final ok = await _plugin.setSerialParameter(
+                      baud: 115200, dataBit: 8, stopBit: 1, parityBit: 0, flow: false,
+                    );
+                    if (!mounted) return;
+                    setState(() => _status = ok ? '已设为 115200/8/1/N' : '设参失败');
+                  },
+                  icon: const Icon(Icons.tune),
+                  label: const Text('波特率115200'),
+                ),
               ],
             ),
             const SizedBox(height: 16),
diff --git a/lib/ch934x_serial.dart b/lib/ch934x_serial.dart
index 421d882..65cf7f7 100644
--- a/lib/ch934x_serial.dart
+++ b/lib/ch934x_serial.dart
@@ -168,4 +168,80 @@ class Ch934xSerial {
     await _platform.setExceptionCallback(controller.add);
     return subscription;
   }
+
+  // ---------------------------------------------------------------------------
+  // 新增接口(文档补充的完整 SDK API)
+  // ---------------------------------------------------------------------------
+
+  /// 设置 Break 信号。
+  Future<bool> setBreak(bool valid) => _platform.setBreak(valid);
+
+  /// 获取当前串口模式。
+  Future<int> getCurrentMode() => _platform.getCurrentMode();
+
+  /// 获取 GPIO 数量。
+  Future<int> getGpiocount(int deviceId) =>
+      _platform.getGpiocount(deviceId);
+
+  /// 获取 GPIO 组数。
+  Future<int> getGpiogroup(int deviceId) =>
+      _platform.getGpiogroup(deviceId);
+
+  /// 使能 GPIO。
+  Future<bool> enableGpio({
+    required int chipType,
+    required int gpioGroup,
+    required int enable,
+  }) =>
+      _platform.enableGpio(
+        chipType: chipType,
+        gpioGroup: gpioGroup,
+        enable: enable,
+      );
+
+  /// 设置 GPIO 方向。
+  Future<bool> setGpioDir({
+    required int gpioGroup,
+    required int gpioNumber,
+    required int dir,
+  }) =>
+      _platform.setGpioDir(
+        gpioGroup: gpioGroup,
+        gpioNumber: gpioNumber,
+        dir: dir,
+      );
+
+  /// 从缓存查询 GPIO 方向。
+  Future<int> queryGpioDirFromCache({
+    required int gpioGroup,
+    required int gpioNumber,
+  }) =>
+      _platform.queryGpioDirFromCache(
+        gpioGroup: gpioGroup,
+        gpioNumber: gpioNumber,
+      );
+
+  /// 查询设备是否已打开。
+  Future<bool> isConnected(int deviceId) =>
+      _platform.isConnected(deviceId);
+
+  /// 获取当前已打开的设备 ID 列表。
+  Future<List<int>> getConnectedDevices() =>
+      _platform.getConnectedDevices();
+
+  /// 配置当前活跃串口的参数。
+  Future<bool> setSerialParameter({
+    required int baud,
+    int dataBit = 8,
+    int stopBit = 1,
+    int parityBit = 0,
+    bool flow = false,
+  }) =>
+      _platform.setSerialParameter(
+        baud: baud,
+        dataBit: dataBit,
+        stopBit: stopBit,
+        parityBit: parityBit,
+        flow: flow,
+      );
 }
diff --git a/lib/ch934x_serial_method_channel.dart b/lib/ch934x_serial_method_channel.dart
index 2de2715..b963bbf 100644
--- a/lib/ch934x_serial_method_channel.dart
+++ b/lib/ch934x_serial_method_channel.dart
@@ -215,6 +215,117 @@ class MethodChannelCh934xSerial extends Ch934xSerialPlatform {
     );
   }
 
+  @override
+  Future<bool> setBreak(bool valid) {
+    return methodChannel.invokeMethod<bool>(
+      'setBreak',
+      <String, Object>{'valid': valid},
+    ).then((v) => v ?? false);
+  }
+
+  @override
+  Future<int> getCurrentMode() {
+    return methodChannel.invokeMethod<int>('getCurrentMode')
+        .then((v) => v ?? -1);
+  }
+
+  @override
+  Future<int> getGpiocount(int deviceId) {
+    return methodChannel.invokeMethod<int>(
+      'getGPIOCount',
+      <String, Object>{'deviceId': deviceId},
+    ).then((v) => v ?? -1);
+  }
+
+  @override
+  Future<int> getGpiogroup(int deviceId) {
+    return methodChannel.invokeMethod<int>(
+      'getGPIOGroup',
+      <String, Object>{'deviceId': deviceId},
+    ).then((v) => v ?? -1);
+  }
+
+  @override
+  Future<bool> enableGpio({
+    required int chipType,
+    required int gpioGroup,
+    required int enable,
+  }) {
+    return methodChannel.invokeMethod<bool>(
+      'enableGPIO',
+      <String, Object>{
+        'chipType': chipType,
+        'gpioGroup': gpioGroup,
+        'enable': enable,
+      },
+    ).then((v) => v ?? false);
+  }
+
+  @override
+  Future<bool> setGpioDir({
+    required int gpioGroup,
+    required int gpioNumber,
+    required int dir,
+  }) {
+    return methodChannel.invokeMethod<bool>(
+      'setGPIODir',
+      <String, Object>{
+        'gpioGroup': gpioGroup,
+        'gpioNumber': gpioNumber,
+        'dir': dir,
+      },
+    ).then((v) => v ?? false);
+  }
+
+  @override
+  Future<int> queryGpioDirFromCache({
+    required int gpioGroup,
+    required int gpioNumber,
+  }) {
+    return methodChannel.invokeMethod<int>(
+      'queryGPIODirFromCache',
+      <String, Object>{
+        'gpioGroup': gpioGroup,
+        'gpioNumber': gpioNumber,
+      },
+    ).then((v) => v ?? -1);
+  }
+
+  @override
+  Future<bool> isConnected(int deviceId) {
+    return methodChannel.invokeMethod<bool>(
+      'isConnected',
+      <String, Object>{'deviceId': deviceId},
+    ).then((v) => v ?? false);
+  }
+
+  @override
+  Future<List<int>> getConnectedDevices() async {
+    final raw = await methodChannel.invokeMethod<List<dynamic>>('getConnectedDevices');
+    if (raw == null) return const <int>[];
+    return raw.whereType<int>().toList(growable: false);
+  }
+
+  @override
+  Future<bool> setSerialParameter({
+    required int baud,
+    int dataBit = 8,
+    int stopBit = 1,
+    int parityBit = 0,
+    bool flow = false,
+  }) {
+    return methodChannel.invokeMethod<bool>(
+      'setSerialParameter',
+      <String, Object>{
+        'baud': baud,
+        'dataBit': dataBit,
+        'stopBit': stopBit,
+        'parityBit': parityBit,
+        'flow': flow,
+      },
+    ).then((v) => v ?? false);
+  }
+
   /// 释放内部资源,通常仅在测试或热重载场景下使用。
   @visibleForTesting
   void dispose() {
diff --git a/lib/ch934x_serial_platform_interface.dart b/lib/ch934x_serial_platform_interface.dart
index 949bf2a..ba0715d 100644
--- a/lib/ch934x_serial_platform_interface.dart
+++ b/lib/ch934x_serial_platform_interface.dart
@@ -112,4 +112,60 @@ abstract class Ch934xSerialPlatform extends PlatformInterface {
   Future<void> setExceptionCallback(
     void Function(Ch934xException exception) onException,
   );
+
+  // ---------------------------------------------------------------------------
+  // 新增接口(文档补充的完整 SDK API)
+  // ---------------------------------------------------------------------------
+
+  /// 设置 Break 信号(对应 `CH934XManager.setBreak`)。
+  Future<bool> setBreak(bool valid);
+
+  /// 获取当前串口模式(对应 `CH934XManager.getCurrentMode`)。
+  /// 返回值见 [Ch934xMode];仅 CH934X 有效,CH348 返回 -1。
+  Future<int> getCurrentMode();
+
+  /// 获取 GPIO 数量(对应 `CH934XManager.getGPIOCount`)。
+  Future<int> getGpiocount(int deviceId);
+
+  /// 获取 GPIO 组数(对应 `CH934XManager.getGPIOGroup`)。
+  Future<int> getGpiogroup(int deviceId);
+
+  /// 使能 GPIO(对应 `CH934XManager.enableGPIO`)。
+  /// [chipType] 由 [Ch934xDeviceType] 常量标识,[gpioGroup] 为组号,
+  /// [enable] 含义见文档: CH9344 传 1/0 控制整组;CH348 使用位掩码。
+  Future<bool> enableGpio({
+    required int chipType,
+    required int gpioGroup,
+    required int enable,
+  });
+
+  /// 设置 GPIO 方向(对应 `CH934XManager.setGPIODir`)。
+  /// [dir] 取值见 [GpioDirection]。
+  Future<bool> setGpioDir({
+    required int gpioGroup,
+    required int gpioNumber,
+    required int dir,
+  });
+
+  /// 从缓存查询 GPIO 方向(对应 `CH934XManager.queryGPIODirFromCache`)。
+  /// 返回值见 [GpioDirection];-1 表示查询失败。
+  Future<int> queryGpioDirFromCache({
+    required int gpioGroup,
+    required int gpioNumber,
+  });
+
+  /// 查询设备是否已打开(对应 `CH934XManager.isConnected`)。
+  Future<bool> isConnected(int deviceId);
+
+  /// 获取当前已打开的设备 ID 列表(对应 `CH934XManager.getConnectedDevices`)。
+  Future<List<int>> getConnectedDevices();
+
+  /// 配置当前活跃串口的参数(对应 `CH934XManager.setSerialParameter`)。
+  Future<bool> setSerialParameter({
+    required int baud,
+    int dataBit = 8,
+    int stopBit = 1,
+    int parityBit = 0,
+    bool flow = false,
+  });
 }
diff --git a/lib/src/models/ch934x_device_type.dart b/lib/src/models/ch934x_device_type.dart
index b5de334..ab30204 100644
--- a/lib/src/models/ch934x_device_type.dart
+++ b/lib/src/models/ch934x_device_type.dart
@@ -26,3 +26,30 @@ class Ch934xDeviceType {
   /// 未知或非 CH934X 设备。
   static const int unknown = -1;
 }
+
+/// 串口当前模式，对应 SDK [Mode] 枚举。
+///
+/// 仅对 CH934X 型号有效（CH348 调用 [Ch934xSerial.getCurrentMode] 无意义）。
+class Ch934xMode {
+  const Ch934xMode._();
+
+  /// 普通模式。
+  static const int normal = 0;
+
+  /// 硬件流控模式。
+  static const int hardflow = 1;
+
+  /// GPIO 模式。
+  static const int gpio = 2;
+}
+
+/// GPIO 方向，对应 SDK [GPIO_DIR] 枚举。
+class GpioDirection {
+  const GpioDirection._();
+
+  /// 输入方向。
+  static const int in_ = 0;
+
+  /// 输出方向。
+  static const int out = 1;
+}