diff --git a/motor_dev/CMakeLists.txt b/motor_dev/CMakeLists.txt
new file mode 100644
index 0000000..5294975
--- /dev/null
+++ b/motor_dev/CMakeLists.txt
@@ -0,0 +1,33 @@
+cmake_minimum_required(VERSION 3.8)
+project(motor_dev)
+
+if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  add_compile_options(-Wall -Wextra -Wpedantic)
+endif()
+
+# find dependencies
+find_package(ament_cmake REQUIRED)
+find_package(std_msgs REQUIRED)
+find_package(rclcpp REQUIRED)
+find_package(rosidl_default_generators REQUIRED)
+rosidl_generate_interfaces(${PROJECT_NAME} "msg/MotorCmd.msg")
+include_directories(include ${CMAKE_CURRENT_BINARY_DIR}/rosidl_generator_cpp)
+add_executable(motor_dev_node src/main.cpp src/rs485_driver.cpp)
+add_dependencies(motor_dev_node ${PROJECT_NAME}__rosidl_typesupport_cpp)
+target_link_libraries(motor_dev_node ${PROJECT_NAME}__rosidl_typesupport_cpp )
+ament_target_dependencies(motor_dev_node rclcpp std_msgs)
+install(TARGETS motor_dev_node DESTINATION lib/${PROJECT_NAME})
+
+if(BUILD_TESTING)
+  find_package(ament_lint_auto REQUIRED)
+  # the following line skips the linter which checks for copyrights
+  # comment the line when a copyright and license is added to all source files
+  set(ament_cmake_copyright_FOUND TRUE)
+  # the following line skips cpplint (only works in a git repo)
+  # comment the line when this package is in a git repo and when
+  # a copyright and license is added to all source files
+  set(ament_cmake_cpplint_FOUND TRUE)
+  ament_lint_auto_find_test_dependencies()
+endif()
+
+ament_package()
diff --git a/motor_dev/include/motor_dev/rs485_driver.hpp b/motor_dev/include/motor_dev/rs485_driver.hpp
new file mode 100644
index 0000000..3cb788a
--- /dev/null
+++ b/motor_dev/include/motor_dev/rs485_driver.hpp
@@ -0,0 +1,61 @@
+#ifndef RS485_DRIVER_HPP
+#define RS485_DRIVER_HPP
+
+#include <string>
+#include <vector>
+#include <termios.h>
+
+namespace motor_dev
+{
+    class RS485Driver
+    {
+    public:
+        RS485Driver();
+        ~RS485Driver();
+        
+        // 打开串口
+        bool openPort(const std::string &port_name, int baud_rate = 115200);
+        
+        // 关闭串口
+        void closePort();
+        
+        // 发送数据
+        bool sendData(const std::vector<uint8_t> &data);
+        
+        // 接收数据
+        bool receiveData(std::vector<uint8_t> &data, size_t max_length, int timeout_ms = 100);
+        //本末
+        int bm_set_mode(uint8_t motor_id, uint8_t mode);
+        int bm_set_pos(uint8_t motor_id, float angle);
+        float bm_get_pos(uint8_t motor_id);
+
+
+        //脉塔
+        void add_crc16(std::vector<uint8_t> &data);
+        int mt_set_pos(uint8_t motor_id, float angle);
+        float mt_get_pos(uint8_t motor_id);
+
+    private:
+        int com_fd_;
+        //bool is_open_;
+        struct termios original_termios_;
+        //size_t max_motors_;
+
+        //size_t control_index_;
+        
+        // 转换波特率
+        speed_t convertBaudRate(int baud_rate);
+
+        // 电机协议常量
+        // static constexpr uint8_t START_BYTE = 0x64;
+        // static constexpr uint8_t STOP_BYTE = 0x55;
+        // static constexpr uint8_t CONTROL_CMD = 0x64;
+        // static constexpr uint8_t ZERO_CMD = 0x00;
+        // static constexpr uint8_t SPEED_CMD = 0x14;
+        // static constexpr uint8_t DEFAULT_TIME = 0x64;
+        // static constexpr uint8_t STOP_CMD = 0x02;
+        // static constexpr uint8_t ALL_MOTORS_CMD = 0x03;
+    };
+}
+
+#endif // RS485_DRIVER_HPP
diff --git a/motor_dev/msg/MotorCmd.msg b/motor_dev/msg/MotorCmd.msg
new file mode 100644
index 0000000..c54cafc
--- /dev/null
+++ b/motor_dev/msg/MotorCmd.msg
@@ -0,0 +1,5 @@
+string target
+string type
+string position
+int32[] motor_id
+float32[] motor_angle
diff --git a/motor_dev/package.xml b/motor_dev/package.xml
new file mode 100644
index 0000000..fae87c6
--- /dev/null
+++ b/motor_dev/package.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0"?>
+<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
+<package format="3">
+  <name>motor_dev</name>
+  <version>0.0.0</version>
+  <description>TODO: Package description</description>
+  <maintainer email="you@example.com">h</maintainer>
+  <license>TODO: License declaration</license>
+
+  <buildtool_depend>ament_cmake</buildtool_depend>
+  <member_of_group>rosidl_interface_packages</member_of_group>
+  <depend>std_msgs</depend>
+  <depend>rclcpp</depend>
+
+  <test_depend>ament_lint_auto</test_depend>
+  <test_depend>ament_lint_common</test_depend>
+
+  <export>
+    <build_type>ament_cmake</build_type>
+  </export>
+</package>
diff --git a/motor_dev/src/main.cpp b/motor_dev/src/main.cpp
new file mode 100644
index 0000000..ec612ec
--- /dev/null
+++ b/motor_dev/src/main.cpp
@@ -0,0 +1,36 @@
+#include"rclcpp/rclcpp.hpp"
+#include"motor_dev/rs485_driver.hpp"
+#include"motor_dev/msg/motor_cmd.hpp"
+using namespace motor_dev;
+RS485Driver rs485_driver_;
+int main(int argc,char* argv[]){
+    rclcpp::init(argc,argv);
+    auto node=rclcpp::Node::make_shared("motor_dev_node");
+    std::cout << "open RS485 port.." << std::endl;
+    if (!rs485_driver_.openPort("/dev/ttyS0", 115200)){
+        std::cout << "Failed to open RS485 port." << std::endl;
+    }
+    //init
+    rs485_driver_.bm_set_mode(1,3);//位置模式
+    auto rs485_sub_=node->create_subscription<motor_dev::msg::MotorCmd>("/motor_cmd",10,[](const motor_dev::msg::MotorCmd::SharedPtr msg){
+            size_t n = msg->motor_id.size();
+            if (msg->target == "rs485") {
+                for (size_t i = 0; i < n; ++i) {
+                    int32_t id       = msg->motor_id[i];
+                    float angle    =msg->motor_angle[i];
+                    std::cout<<"recv:"<<msg->type<<","<<id<<","<<angle<<std::endl;
+                    if(msg->type=="bm"){
+                        rs485_driver_.bm_set_pos(id,angle);
+                    }else if(msg->type=="mt"){
+                        rs485_driver_.mt_set_pos(id,angle);
+                    }
+                }
+            }else if(msg->target=="ethercat"){
+                //TODO
+            }
+        });
+
+    rs485_driver_.closePort();
+    rclcpp::spin(node);
+    rclcpp::shutdown();
+}
\ No newline at end of file
diff --git a/motor_dev/src/rs485_driver.cpp b/motor_dev/src/rs485_driver.cpp
new file mode 100644
index 0000000..1023004
--- /dev/null
+++ b/motor_dev/src/rs485_driver.cpp
@@ -0,0 +1,340 @@
+#include "motor_dev/rs485_driver.hpp"
+#include <fcntl.h>
+#include <unistd.h>
+#include <cstring>
+#include <iostream>
+#include <chrono>
+#include <thread>
+#include "motor_dev/rs485_driver.hpp"
+
+namespace motor_dev
+{
+
+    const unsigned char CRC8Table[]={  
+        0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,  
+        157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,  
+        35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98,  
+        190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255,  
+        70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7,  
+        219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154,  
+        101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36,  
+        248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185,  
+        140, 210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113, 147, 205,  
+        17, 79, 173, 243, 112, 46, 204, 146, 211, 141, 111, 49, 178, 236, 14, 80,  
+        175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82, 176, 238,  
+        50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115,  
+        202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139,  
+        87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22,  
+        233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168,  
+        116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53  
+    }; 
+    /**
+        *	@name		CRC8_Table
+    * @brief  This function is used to Get CRC8 check value.
+        * @param  p :Array pointer. counter :Number of array elements.
+    * @retval crc8
+    */
+    unsigned char CRC8_Table(unsigned char *p, int counter)  
+    {  
+        unsigned char crc8 = 0;  
+    
+        for( ; counter > 0; counter--)
+        {  
+        crc8 = CRC8Table[crc8^*p];  
+        p++;  
+        }  
+        return(crc8);  
+    }
+
+    RS485Driver::RS485Driver()
+    {
+
+    }
+    
+    RS485Driver::~RS485Driver()
+    {
+        closePort();
+    }
+    
+    speed_t RS485Driver::convertBaudRate(int baud_rate)
+    {
+        switch (baud_rate)
+        {
+            case 9600: return B9600;
+            case 19200: return B19200;
+            case 38400: return B38400;
+            case 57600: return B57600;
+            case 115200: return B115200;
+            case 230400: return B230400;
+            case 460800: return B460800;
+            case 500000: return B500000;
+            case 576000: return B576000;
+            case 921600: return B921600;
+            default: return B0;
+        }
+    }
+    
+    bool RS485Driver::openPort(const std::string &port_name, int baud_rate)
+    {
+        // 打开串口
+        com_fd_ = open(port_name.c_str(), O_RDWR | O_NOCTTY | O_NDELAY);
+        if (com_fd_ == -1)
+        {
+            std::cerr << "无法打开串口: " << port_name << std::endl;
+            return false;
+        }
+        
+        // 保存原始配置
+        if (tcgetattr(com_fd_, &original_termios_) == -1)
+        {
+            std::cerr << "无法获取串口属性" << std::endl;
+            close(com_fd_);
+            com_fd_ = -1;
+            return false;
+        }
+        
+        // 配置串口
+        struct termios tty;
+        memset(&tty, 0, sizeof(tty));
+        
+        // 设置波特率
+        speed_t speed = convertBaudRate(baud_rate);
+        if (speed == B0)
+        {
+            std::cerr << "不支持的波特率: " << baud_rate << std::endl;
+            closePort();
+            return false;
+        }
+        
+        cfsetospeed(&tty, speed);
+        cfsetispeed(&tty, speed);
+        
+        // 8位数据位，无奇偶校验，1位停止位
+        tty.c_cflag &= ~PARENB;  // 无奇偶校验
+        tty.c_cflag &= ~CSTOPB;  // 1位停止位
+        tty.c_cflag &= ~CSIZE;   // 清除数据位设置
+        tty.c_cflag |= CS8;      // 8位数据位
+        
+        // 禁用硬件流控制
+        tty.c_cflag &= ~CRTSCTS;
+        
+        // 启用接收器，设置本地模式
+        tty.c_cflag |= (CLOCAL | CREAD);
+        
+        // 禁用软件流控制
+        tty.c_iflag &= ~(IXON | IXOFF | IXANY);
+        
+        // 原始输入模式
+        tty.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
+        
+        // 原始输出模式
+        tty.c_oflag &= ~OPOST;
+        
+        // 设置读取超时
+        tty.c_cc[VTIME] = 10;  // 1秒超时
+        tty.c_cc[VMIN] = 0;
+        
+        // 应用配置
+        if (tcsetattr(com_fd_, TCSANOW, &tty) != 0)
+        {
+            std::cerr << "无法设置串口属性" << std::endl;
+            closePort();
+            return false;
+        }
+        std::cout << "串口 " << port_name << " 已打开，波特率: " << baud_rate << std::endl;
+        return true;
+    }
+    
+    void RS485Driver::closePort()
+    {
+        if (com_fd_>0)
+        {
+            // 恢复原始配置
+            tcsetattr(com_fd_, TCSANOW, &original_termios_);
+            close(com_fd_);
+            com_fd_ = -1;
+            std::cout << "串口已关闭" << std::endl;
+        }
+    }
+    
+    bool RS485Driver::sendData(const std::vector<uint8_t> &data)
+    {
+        ssize_t bytes_written = write(com_fd_, data.data(), data.size());
+        if (bytes_written != static_cast<ssize_t>(data.size()))
+        {
+            std::cerr << "rs485,fd:"<<com_fd_<<",发送ERR:" <<bytes_written<<"/"<<data.size()<<std::endl; 
+            return false;
+        }
+        
+        return true;
+    }
+    
+    bool RS485Driver::receiveData(std::vector<uint8_t> &data, size_t max_length, int timeout_ms)
+    {
+        data.clear();
+        uint8_t buffer[256];
+        ssize_t bytes_read;
+        auto start_time = std::chrono::steady_clock::now();
+        
+        while (data.size() < max_length)
+        {
+            // 检查超时
+            auto current_time = std::chrono::steady_clock::now();
+            auto elapsed_ms = std::chrono::duration_cast<std::chrono::milliseconds>(
+                current_time - start_time).count();
+            
+            if (elapsed_ms >= timeout_ms)
+            {
+                break;  // 超时
+            }
+            
+            // 尝试读取数据
+            bytes_read = read(com_fd_, buffer, std::min(sizeof(buffer), max_length - data.size()));
+            
+            if (bytes_read > 0)
+            {
+                data.insert(data.end(), buffer, buffer + bytes_read);
+                start_time = std::chrono::steady_clock::now();  // 重置超时计时器
+            }
+            else if (bytes_read < 0)
+            {
+                std::cerr << "接收数据错误" << std::endl;
+                return false;
+            }
+            else
+            {
+                // 没有数据，短暂休眠
+                std::this_thread::sleep_for(std::chrono::milliseconds(10));
+            }
+        }
+        
+        return !data.empty();
+    }
+    int RS485Driver::bm_set_mode(uint8_t motor_id, uint8_t mode){
+        std::vector<uint8_t> command;
+        if(mode>3)
+            mode=3;
+        command.push_back(motor_id);
+        command.push_back(0xa0);
+        command.push_back(0);
+        command.push_back(0);
+        command.push_back(0);
+        command.push_back(0);
+        command.push_back(0);
+        command.push_back(0);
+        command.push_back(0);
+        command.push_back(mode);
+        return 0;
+    }
+    
+    int RS485Driver::bm_set_pos(uint8_t motor_id, float angle){
+        std::vector<uint8_t> command;
+        if(angle>360.0)
+            angle=360.0;
+        int32_t pos=angle*32767/360.0;
+        uint8_t high_byte = (pos >> 8) & 0xFF;  // 高8位
+        uint8_t low_byte  = pos & 0xFF;         // 低8位
+        command.push_back(motor_id);
+        command.push_back(0x64);
+        command.push_back(high_byte);
+        command.push_back(low_byte);
+        command.push_back(0);
+        command.push_back(0);
+        command.push_back(0x64);
+        command.push_back(0);
+        unsigned char crc8 = CRC8_Table(command.data(), 9);
+        command.push_back(crc8);
+        bool ret = sendData(command);
+        return 0;
+    }
+    float RS485Driver::bm_get_pos(uint8_t motor_id){
+        std::vector<uint8_t> command;
+        command.push_back(motor_id);
+        command.push_back(0x74);
+        command.push_back(0);
+        command.push_back(0);
+        command.push_back(0);
+        command.push_back(0);
+        command.push_back(0);
+        command.push_back(0);
+        unsigned char crc8 = CRC8_Table(command.data(), 9);
+        command.push_back(crc8);
+        bool ret = sendData(command);
+        if(ret){
+            std::vector<uint8_t> data;
+            bool ret=receiveData(data, 20, 1000);
+            if(ret){
+                uint8_t pos = data[7];
+                float angle = pos * 360.0 /255.0;
+                return angle;
+            }
+        }
+        return -1;
+    }
+    //mt
+    void RS485Driver::add_crc16(std::vector<uint8_t>& data) {
+        uint16_t crc = 0xFFFF;
+        for (uint8_t byte : data) {
+            crc ^= byte;
+            for (int i = 0; i < 8; i++) {
+                if (crc & 0x0001) {
+                    crc >>= 1;
+                    crc ^= 0xA001;
+                } else {
+                    crc >>= 1;
+                }
+            }
+        }
+        data.push_back(static_cast<uint8_t>(crc & 0xFF));
+        data.push_back(static_cast<uint8_t>((crc >> 8) & 0xFF));
+    }
+
+    //
+    int RS485Driver::mt_set_pos(uint8_t motor_id, float angle){
+        std::vector<uint8_t> packet;
+        packet.push_back(0x3e);
+        packet.push_back(motor_id);
+        packet.push_back(0x08);
+
+        uint16_t pos = static_cast<uint16_t>(angle * 100);
+        uint8_t low=pos & 0xff;
+        uint8_t high=(pos>>8)&0xff;
+        packet.push_back(0xa6);
+        packet.push_back(0x00);//方向
+        packet.push_back(0x01);
+        packet.push_back(0x00);//速度
+        packet.push_back(low);//位置,pos的低8位
+        packet.push_back(high);//位置，pos的高8位
+        packet.push_back(0);
+        packet.push_back(0x0);
+        add_crc16(packet);
+        return 0;
+    }
+    float RS485Driver::mt_get_pos(uint8_t motor_id){
+        std::vector<uint8_t> packet;
+        packet.push_back(0x3e);
+        packet.push_back(motor_id);
+        packet.push_back(0x08);
+        //
+        packet.push_back(0x94);
+        packet.push_back(0);
+        packet.push_back(0);
+        packet.push_back(0);
+        packet.push_back(0);
+        packet.push_back(0);
+        packet.push_back(0);
+        packet.push_back(0);
+        add_crc16(packet);
+        bool ret=sendData(packet);
+        if(ret){
+            std::vector<uint8_t> data;
+            ret=receiveData(data, 20, 1000);
+            if(ret){
+                uint32_t pos = (data[7]<<8)+(data[6]&0xff);
+                float angle = pos /100.0;
+                return angle;
+            }
+        }
+        return -1;
+    }
+}