|
|
@@ -0,0 +1,280 @@
|
|
|
+# 1.控制OLED-自定义消息接口
|
|
|
+
|
|
|
+ 你好，我是爱吃鱼香ROS的小鱼。前面章节中我们使用ROS2提供的两数相加服务接口实现了服务通信，但是很多场景需要我们自定定义接口，所以本节我们就学习如何自定义MicroROS的接口，以及如何将自己的功能包添加到MicroROS中来。
|
|
|
+
|
|
|
+本节课最终效果是：通过自定义的服务接口控制开发板上的OLED显示器的内容。
|
|
|
+
|
|
|
+```
|
|
|
+ros2 service call /oled_control fishbot_interfaces/srv/OledControl "{px: 0, py: 0 ,data: 'oled control by service~'}"
|
|
|
+```
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+## 一、新建工程添加依赖
|
|
|
+
|
|
|
+新建`example14_custom_interface`
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+修改`platformio.ini`
|
|
|
+
|
|
|
+```ini
|
|
|
+[env:featheresp32]
|
|
|
+platform = espressif32
|
|
|
+board = featheresp32
|
|
|
+framework = arduino
|
|
|
+lib_deps =
|
|
|
+ https://gitee.com/ohhuo/micro_ros_platformio.git
|
|
|
+ adafruit/Adafruit SSD1306@^2.5.7
|
|
|
+```
|
|
|
+
|
|
|
+这里除了添加micro_ros库之外再添加oled驱动库。
|
|
|
+
|
|
|
+## 二、添加自定义接口
|
|
|
+
|
|
|
+**添加自定义接口一共需要三步。**
|
|
|
+
|
|
|
+**1.创建`extra_packages`文件夹并创建接口功能包**
|
|
|
+
|
|
|
+**2.编译功能包（主要为了测试功能包是否正常）**
|
|
|
+
|
|
|
+**3.删除`.pio/libdeps/featheresp32/micro_ros_platformio/libmicroros`文件夹，重新编译**
|
|
|
+
|
|
|
+### 2.1 创建功能包
|
|
|
+
|
|
|
+在工程的主目录下创建`extra_packages`文件夹，接着在文件夹下创建`fishbot_interfaces`功能包
|
|
|
+
|
|
|
+```shell
|
|
|
+cd example14_custom_interface
|
|
|
+mkdir extra_packages
|
|
|
+cd extra_packages
|
|
|
+ros2 pkg create fishbot_interfaces
|
|
|
+```
|
|
|
+
|
|
|
+接着添加服务接口文件并修改CMakeLists.txt
|
|
|
+
|
|
|
+文件`extra_packages/fishbot_interfaces/srv/OledControl.srv`
|
|
|
+
|
|
|
+```
|
|
|
+int32 px
|
|
|
+int32 py
|
|
|
+string data
|
|
|
+---
|
|
|
+int32 result
|
|
|
+```
|
|
|
+
|
|
|
+文件`extra_packages/fishbot_interfaces/CMakeLists.txt`
|
|
|
+
|
|
|
+```cmake
|
|
|
+cmake_minimum_required(VERSION 3.5)
|
|
|
+project(fishbot_interfaces)
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+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)
|
|
|
+# uncomment the following section in order to fill in
|
|
|
+# further dependencies manually.
|
|
|
+# find_package(<dependency> REQUIRED)
|
|
|
+
|
|
|
+if(BUILD_TESTING)
|
|
|
+ find_package(ament_lint_auto REQUIRED)
|
|
|
+ # the following line skips the linter which checks for copyrights
|
|
|
+ # uncomment the line when a copyright and license is not present in all source files
|
|
|
+ #set(ament_cmake_copyright_FOUND TRUE)
|
|
|
+ # the following line skips cpplint (only works in a git repo)
|
|
|
+ # uncomment the line when this package is not in a git repo
|
|
|
+ #set(ament_cmake_cpplint_FOUND TRUE)
|
|
|
+ ament_lint_auto_find_test_dependencies()
|
|
|
+endif()
|
|
|
+
|
|
|
+find_package(rosidl_default_generators REQUIRED)
|
|
|
+
|
|
|
+rosidl_generate_interfaces(${PROJECT_NAME}
|
|
|
+ "srv/OledControl.srv"
|
|
|
+ )
|
|
|
+
|
|
|
+ament_package()
|
|
|
+
|
|
|
+```
|
|
|
+
|
|
|
+## 2.2 编译功能包
|
|
|
+
|
|
|
+```shell
|
|
|
+cd extra_packages/
|
|
|
+colcon build
|
|
|
+```
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+### 2.3 重新编译工程
|
|
|
+
|
|
|
+编译前需要删除`.pio/libdeps/featheresp32/micro_ros_platformio/libmicroros`文件夹，使用Ctrl+Alt+B重新重新编译工程。
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+## 三、编写代码
|
|
|
+
|
|
|
+和两数相加服务相似的代码，只不过更换了接口并添加了OLED的驱动。
|
|
|
+
|
|
|
+```c++
|
|
|
+#include <Arduino.h>
|
|
|
+#include <micro_ros_platformio.h>
|
|
|
+
|
|
|
+#include <rcl/rcl.h>
|
|
|
+#include <rclc/rclc.h>
|
|
|
+#include <rclc/executor.h>
|
|
|
+#include <micro_ros_utilities/string_utilities.h>
|
|
|
+
|
|
|
+#include "Wire.h"
|
|
|
+#include <Adafruit_GFX.h> // 加载Adafruit_GFX库
|
|
|
+#include <Adafruit_SSD1306.h> // 加载Adafruit_SSD1306库
|
|
|
+
|
|
|
+#include <fishbot_interfaces/srv/oled_control.h> // 添加接口
|
|
|
+
|
|
|
+rclc_executor_t executor;
|
|
|
+rclc_support_t support;
|
|
|
+rcl_allocator_t allocator;
|
|
|
+rcl_node_t node;
|
|
|
+// 定义服务
|
|
|
+rcl_service_t service;
|
|
|
+
|
|
|
+// 服务请求和返回消息定义
|
|
|
+fishbot_interfaces__srv__OledControl_Request req;
|
|
|
+fishbot_interfaces__srv__OledControl_Response res;
|
|
|
+
|
|
|
+Adafruit_SSD1306 display;
|
|
|
+
|
|
|
+// 服务回调函数
|
|
|
+void service_callback(const void *req, void *res)
|
|
|
+{
|
|
|
+ fishbot_interfaces__srv__OledControl_Request *req_in = (fishbot_interfaces__srv__OledControl_Request *)req;
|
|
|
+ fishbot_interfaces__srv__OledControl_Response *res_in = (fishbot_interfaces__srv__OledControl_Response *)res;
|
|
|
+ // 计算sum
|
|
|
+ display.clearDisplay(); // 清空屏幕
|
|
|
+ display.setCursor(req_in->px, req_in->py); // 设置开始显示文字的坐标
|
|
|
+ display.println(req_in->data.data); // 输出的字符
|
|
|
+ display.display();
|
|
|
+ res_in->result = 0;
|
|
|
+}
|
|
|
+
|
|
|
+void setup()
|
|
|
+{
|
|
|
+ Serial.begin(115200);
|
|
|
+ // 设置通过串口进行MicroROS通信
|
|
|
+ set_microros_serial_transports(Serial);
|
|
|
+ // 延时时一段时间，等待设置完成
|
|
|
+ delay(2000);
|
|
|
+ // 初始化内存分配器
|
|
|
+ allocator = rcl_get_default_allocator();
|
|
|
+ // 创建初始化选项
|
|
|
+ rclc_support_init(&support, 0, NULL, &allocator);
|
|
|
+ // 创建节点 hello_microros
|
|
|
+ rclc_node_init_default(&node, "example14_interface", "", &support);
|
|
|
+ // 使用默认配置创建服务
|
|
|
+ rclc_service_init_default(&service, &node, ROSIDL_GET_SRV_TYPE_SUPPORT(fishbot_interfaces, srv, OledControl), "/oled_control");
|
|
|
+ // 创建执行器
|
|
|
+ rclc_executor_init(&executor, &support.context, 1, &allocator);
|
|
|
+ // 执行器添加服务
|
|
|
+ rclc_executor_add_service(&executor, &service, &req, &res, service_callback);
|
|
|
+ // 重要，为string类型消息分配空间
|
|
|
+ req.data = micro_ros_string_utilities_init_with_size(100);
|
|
|
+
|
|
|
+ /*========================OLED初始化====================================*/
|
|
|
+ Wire.begin(18, 19);
|
|
|
+ display = Adafruit_SSD1306(128, 64, &Wire);
|
|
|
+ display.begin(SSD1306_SWITCHCAPVCC, 0x3C); // 设置OLED的I2C地址
|
|
|
+ display.clearDisplay(); // 清空屏幕
|
|
|
+ display.setTextSize(1); // 设置字体大小
|
|
|
+ display.setCursor(0, 0); // 设置开始显示文字的坐标
|
|
|
+ display.setTextColor(SSD1306_WHITE); // 设置字体颜色
|
|
|
+ display.println("hello fishros!"); // 输出的字符
|
|
|
+ display.display();
|
|
|
+}
|
|
|
+
|
|
|
+void loop()
|
|
|
+{
|
|
|
+ delay(100);
|
|
|
+ // 循环处理数据
|
|
|
+ rclc_executor_spin_some(&executor, RCL_MS_TO_NS(100));
|
|
|
+}
|
|
|
+```
|
|
|
+
|
|
|
+## 四、代码讲解
|
|
|
+
|
|
|
+这里对新增的几行主要代码进行讲解
|
|
|
+
|
|
|
+- `#include <micro_ros_utilities/string_utilities.h> 添加string工具类`
|
|
|
+- ` req.data = micro_ros_string_utilities_init_with_size(100); 使用string类型内存分配工具为data分配100字节e的空间`
|
|
|
+
|
|
|
+**主要就是这两部分，值得注意的是，如果不提前为string类型的数据分配内容空间，最终会导致无法正常接收数据。**
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+## 五、下载测试
|
|
|
+
|
|
|
+### 5.1 编译下载
|
|
|
+
|
|
|
+连接开发板，编译下载。
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+### 5.2 启动Agent
|
|
|
+
|
|
|
+接着打开终端启动agent
|
|
|
+
|
|
|
+```shell
|
|
|
+sudo docker run -it --rm -v /dev:/dev -v /dev/shm:/dev/shm --privileged --net=host microros/micro-ros-agent:$ROS_DISTRO serial --dev /dev/ttyUSB0 -v
|
|
|
+```
|
|
|
+
|
|
|
+点击下RST按钮，重启开发板，正常可以看到下图内容
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+### 5.3 查看是否连通
|
|
|
+
|
|
|
+接着打开终端查看节点和话题
|
|
|
+
|
|
|
+```shell
|
|
|
+ros2 node list
|
|
|
+ros2 service list
|
|
|
+```
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+### 4.4 测试控制
|
|
|
+
|
|
|
+进入`extra_packages`，source环境
|
|
|
+
|
|
|
+```
|
|
|
+source install/setup.bash
|
|
|
+```
|
|
|
+
|
|
|
+显示`nihao`
|
|
|
+
|
|
|
+```shell
|
|
|
+ros2 service call /oled_control fishbot_interfaces/srv/OledControl "{px: 0, py: 0 , data: 'nihao'}"
|
|
|
+```
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+显示`oled control by service~`
|
|
|
+
|
|
|
+```
|
|
|
+ros2 service call /oled_control fishbot_interfaces/srv/OledControl "{px: 0, py: 0 ,data: 'oled control by service~'}"
|
|
|
+```
|
|
|
+
|
|
|
+
|
|
|
+
|
|
|
+## 六、总结
|
|
|
+
|
|
|
+本节通过使用自定义服务接口控制oled显示的例程，学习了如何在工程中添加自己的功能包和接口文件。下一节我们将学习如何让开发板的时间和上位机的时间进行同步。
|
|
|
+
|
|
|
+
|
|
|
+
|
鱼香ROS
