# Eskin Finger SDK

E-Skin 手指力传感器 Rust SDK，提供串口通信、寄存器读写、流式采集能力，支持 Rust / C/C++ / Python 调用。

## 目录结构

```text
src/
  lib.rs          — Rust 库入口
  device.rs       — 设备管理（open/close/read/write）
  stream.rs       — 流式采集（PollingSampleCollector）
  protocol.rs     — 协议帧编解码（CRC-8/X25）
  register.rs     — 寄存器地址定义与解析
  transport.rs    — 串口传输抽象
  channel.rs      — 线程间 Channel
  config.rs       — 配置与设备信息
  error.rs        — 错误类型
  types.rs        — 数据类型定义
  ffi/mod.rs      — C FFI 导出函数

include/
  eskin_ffi.h     — C/C++ 头文件

example/
  cpp/main.cpp    — C++ 使用示例
  python/         — Python 使用示例
```

---

## 快速开始（Rust）

```rust
use eskin_finger_sdk::config::DeviceConfig;
use eskin_finger_sdk::device::{EskinDevice, EskinDeviceInner};
use eskin_finger_sdk::transport::SerialPortTransport;

let transport = SerialPortTransport::new("/dev/ttyUSB0", 921600);
let config = DeviceConfig::default();
let mut device = EskinDeviceInner::new(config, Box::new(transport));
device.open().unwrap();

// 读寄存器（原始字节）
let data = device.read_register(0x0000, 4).unwrap();
println!("Serial: {:?}", data);

// 写寄存器
let count = device.write_register(0x0030, &[0x01, 0x00, 0x00, 0x00]).unwrap();
println!("Wrote {} bytes", count);

device.close().unwrap();
```

---

## 使用 C/C++

### 构建动态库

```bash
# 安装依赖（Ubuntu）
sudo apt install pkg-config libudev-dev

# 构建
cargo build --release
# 输出: target/release/libeskin_finger_sdk.so
```

### 编译 C++ 示例

```bash
g++ example/cpp/main.cpp -I include -L target/release -leskin_finger_sdk -o example_cpp
LD_LIBRARY_PATH=target/release ./example_cpp
```

### C++ 代码示例

```cpp
#include "eskin_ffi.h"
#include <cstdio>

int main() {
    EskinDeviceHandle dev = eskin_open("/dev/ttyUSB0", nullptr);
    if (!dev) return 1;

    uint8_t buf[256];
    uint32_t actual;
    if (eskin_read_register(dev, 0x0000, 4, buf, sizeof(buf), &actual) == ESkinSuccess) {
        printf("Serial: %02X %02X %02X %02X\n", buf[0], buf[1], buf[2], buf[3]);
    }

    eskin_close(dev);
    return 0;
}
```

---

## 使用 Python

```bash
cargo build --release
cd example/python
LD_LIBRARY_PATH=../../target/release python3 example.py
```

```python
from eskin_ffi import EskinDevice

with EskinDevice("target/release/libeskin_finger_sdk.so") as dev:
    dev.open("/dev/ttyUSB0")

    # 读寄存器
    data = dev.read_register(0x0000, 4)
    print(f"Serial: {data.hex()}")

    # 写寄存器
    dev.write_register(0x0030, bytes([0x01, 0x00, 0x00, 0x00]))
```

---

## FFI 接口一览

| 函数 | 说明 |
|------|------|
| `eskin_version()` | 获取 SDK 版本 |
| `eskin_open(path, config)` | 打开串口设备，返回 handle |
| `eskin_close(handle)` | 关闭设备，释放 handle |
| `eskin_read_register(handle, addr, length, buf, buf_len, actual_len)` | 读寄存器原始字节 |
| `eskin_write_register(handle, addr, data, data_len, return_count)` | 写寄存器原始字节 |

---

## 协议格式

### Request 帧

```text
[start:2B] [data_len:2B LE] [dev_addr:1B] [reserved:1B] [func:1B]
[start_addr:4B LE] [read/write_len:2B LE] [payload:NB] [crc:1B]

start = [0x55, 0xAA]
func: READ=0xFB, WRITE=0x79
```

### Response 帧

```text
[start:2B] [data_len:2B LE] [dev_addr:1B] [reserved:1B] [func:1B]
[start_addr:4B LE] [read/write_len:2B LE] [payload:NB] [status:1B] [crc:1B]

start = [0x55, 0xAA]  (注: 0xAA55 LE)
func: RESPONSE_READ=0xFF, RESPONSE_WRITE=0xF9
status: 0x00=Success
```

---

## 错误码

| 名称 | 值 | 说明 |
|------|----|------|
| `Success` | 0 | 成功 |
| `InvalidPointer` | 1 | 空指针 |
| `DeviceNotFound` | 2 | 设备未找到 |
| `DeviceAlreadyOpen` | 3 | 设备已打开 |
| `NotInitialized` | 4 | 未初始化 |
| `AlreadyStreaming` | 5 | 已在采集中 |
| `NotStreaming` | 6 | 未在采集 |
| `Timeout` | 9 | 读超时 |
| `ChannelClosed` | 10 | 通道断开 |
| `CrcError` | 14 | CRC 校验失败 |
| `FrameError` | 15 | 帧格式错误 |
| `DeviceError` | 17 | 设备返回错误 |

---

## 测试

```bash
cargo test                   # 全部测试
cargo test protocol::tests   # 仅协议层
```

---

## 架构

```text
User / C / Python
       ↓ FFI
  DeviceWrapper (handle)
       ↓
  EskinDeviceInner
       ↓ read_register / write_register
  EskinProtocolCodec (encode/decode + CRC8)
       ↓
  SerialTransport (write/read bytes)
       ↓
  Hardware (UART)
```

详细设计见 `docs/PROGRESS.md` 和 `docs/ARCHITECTURE.md`。

---

## 依赖

- `serialport` — 串口访问（需要 `pkg-config` + `libudev-dev`）
- `crc` — CRC-8/X25 校验
- `crossbeam-channel` — 高性能线程间通信
- `chrono` — 时间戳
- `serde` / `serde_json` — 序列化（可选）