开发板漂流计划之小车控制由简入繁之按键控制
人工智能 2025-10-08 21:33:54
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想了解更多内容，开发控制请访问：
和华为官方合作共建的板漂鸿蒙技术社区
https://harmonyos.51cto.com
1.简介
实现最简单的按键控制小车前进、后退、流计左转、小车右转、由简停止的入繁Demo，代码在openharmonny1.10 和openharmony3.00 测试可以正常工作。按制
2. 功能介绍
1).短按 OLED 扩展板S1按键 - 前进
2).长按 OLED 扩展板S1按键 - 左转
3).短按 OLED 扩展板S2按键 - 后退
4).长按 OLED 扩展板S2按键 - 右转
5).短按核心板User按键 - 停止
3.电机的键控控制代码
3.1 电机的控制需要用到PWM，所以需要先将PWM 功能开启，开发控制开启方式如下
device/hisilicon/hispark_pegasus/sdk_liteos/build/config/usr_config.mk
# CONFIG_PWM_SUPPORT is not set改为
CONFIG_PWM_SUPPORT=y3.2 电机的板漂控制代码
电机控制代码是云服务器从润和Gitee小车样例代码car_control.c和car_control.h 修改而来。
主要修改如下
将car_control.c中
#include <app_demo_robot_car.h> extern hi_u32 g_car_speed;移除app_demo_robot_car.h和extern ，流计改为如下
hi_u16 g_car_speed;在car_control.h中添加以下define
#define MAX_SPEED (100) #define MIN_SPEED (30000) #define PWM_DUTY_LEFT_RIGHT (5000) #define PWM_DUTY_FORWARD_BACK (10000)小车前进
/*car go forward */ hi_void car_go_forward(hi_void) { correct_car_speed(); gpio_control(HI_IO_NAME_GPIO_0,小车 HI_GPIO_IDX_0, HI_GPIO_DIR_OUT, HI_GPIO_VALUE1, HI_IO_FUNC_GPIO_0_GPIO); pwm_control(HI_IO_NAME_GPIO_1,HI_IO_FUNC_GPIO_1_PWM4_OUT,HI_PWM_PORT_PWM4, g_car_speed); gpio_control(HI_IO_NAME_GPIO_9, HI_GPIO_IDX_9, HI_GPIO_DIR_OUT, HI_GPIO_VALUE1, HI_IO_FUNC_GPIO_9_GPIO); pwm_control(HI_IO_NAME_GPIO_10,HI_IO_FUNC_GPIO_10_PWM1_OUT,HI_PWM_PORT_PWM1, g_car_speed); }小车后退
/*car go back */ hi_void car_go_back(hi_void) { correct_car_speed(); pwm_control(HI_IO_NAME_GPIO_0,HI_IO_FUNC_GPIO_0_PWM3_OUT,HI_PWM_PORT_PWM3, g_car_speed); gpio_control(HI_IO_NAME_GPIO_1, HI_GPIO_IDX_1, HI_GPIO_DIR_OUT, HI_GPIO_VALUE1, HI_IO_FUNC_GPIO_1_GPIO); pwm_control(HI_IO_NAME_GPIO_9,HI_IO_FUNC_GPIO_9_PWM0_OUT,HI_PWM_PORT_PWM0, g_car_speed); gpio_control(HI_IO_NAME_GPIO_10, HI_GPIO_IDX_10, HI_GPIO_DIR_OUT, HI_GPIO_VALUE1, HI_IO_FUNC_GPIO_10_GPIO); }小车左转
/*car turn left */ hi_void car_turn_left(hi_void) { correct_car_speed(); pwm_control(HI_IO_NAME_GPIO_0,HI_IO_FUNC_GPIO_0_PWM3_OUT,HI_PWM_PORT_PWM3, PWM_DUTY_LEFT_RIGHT); gpio_control(HI_IO_NAME_GPIO_1, HI_GPIO_IDX_1, HI_GPIO_DIR_OUT, HI_GPIO_VALUE0, HI_IO_FUNC_GPIO_1_GPIO); gpio_control(HI_IO_NAME_GPIO_9, HI_GPIO_IDX_9, HI_GPIO_DIR_OUT, HI_GPIO_VALUE1, HI_IO_FUNC_GPIO_9_GPIO); pwm_control(HI_IO_NAME_GPIO_10,HI_IO_FUNC_GPIO_10_PWM1_OUT,HI_PWM_PORT_PWM1, PWM_DUTY_LEFT_RIGHT); }小车右转
/*car turn right */ hi_void car_turn_right(hi_void) { correct_car_speed(); gpio_control(HI_IO_NAME_GPIO_0, HI_GPIO_IDX_0, HI_GPIO_DIR_OUT, HI_GPIO_VALUE1, HI_IO_FUNC_GPIO_0_GPIO); pwm_control(HI_IO_NAME_GPIO_1,HI_IO_FUNC_GPIO_1_PWM4_OUT,HI_PWM_PORT_PWM4, PWM_DUTY_LEFT_RIGHT); pwm_control(HI_IO_NAME_GPIO_9,HI_IO_FUNC_GPIO_9_PWM0_OUT,HI_PWM_PORT_PWM0,PWM_DUTY_LEFT_RIGHT); gpio_control(HI_IO_NAME_GPIO_10, HI_GPIO_IDX_10, HI_GPIO_DIR_OUT, HI_GPIO_VALUE0, HI_IO_FUNC_GPIO_10_GPIO); }小车停止
/*car stop */ hi_void car_stop(hi_void) { correct_car_speed(); pwm_control(HI_IO_NAME_GPIO_0,HI_IO_FUNC_GPIO_0_PWM3_OUT,HI_PWM_PORT_PWM3, PWM_DUTY_STOP); gpio_control(HI_IO_NAME_GPIO_1, HI_GPIO_IDX_1, HI_GPIO_DIR_OUT, HI_GPIO_VALUE0, HI_IO_FUNC_GPIO_1_GPIO); pwm_control(HI_IO_NAME_GPIO_9,HI_IO_FUNC_GPIO_9_PWM0_OUT,HI_PWM_PORT_PWM0, PWM_DUTY_STOP); gpio_control(HI_IO_NAME_GPIO_10, HI_GPIO_IDX_10, HI_GPIO_DIR_OUT, HI_GPIO_VALUE0, HI_IO_FUNC_GPIO_10_GPIO); }4. 按键长按短按功能能的实现
按键功能的实现唐佐林老师已经做了很深入的分享，我这边也是由简参考唐老师的分享来实现的，
附上唐老师的入繁帖子链接：
实现按键“按下事件”和“释放事件”的通用框架(V0.0.1)
实现物理按键的“长按事件”(按键通用框架 V0.0.2)
实现S1，S2，亿华云按制User三个物理按键的独立事件-上(解决思路分析)
实现S1，S2，User三个物理按键的独立事件-下(DTButton-V0.0.3)
本案例中按键功能实现在KeyEvent.c和KeyEvent.h
4.1 主要函数介绍在KeyEvent.h中
/* Description: Key event callback function pointer type. Parameter: id -- key id event -- key event type Return Value: 0 -- Success other -- Failure */ typedef void (*PKeyEventCallback)(KEY_ID_TYPE keyid, KEY_EVENT_TYPE event); /* Description: initialize key event process context. Parameter: None Return Value: 0 -- Success other -- Failure */ int KeyEvent_Init(void); /* Description: To register callback functions for a GPIO key. Parameter: name -- target GPIO port name for a phisical key callback -- callback function for key event event -- the target key event to trigger callback Return Value: 0 -- Success other -- Failure */ int KeyEvent_Connect(const char* name, PKeyEventCallback callback, unsigned int event); /* Description: To unregister callback functions for a GPIO key. Parameter: name -- target GPIO port name for a phisical key Return Value: None */ void KeyEvent_Disconnect(const char* name); /* Description: To close key event process context. Parameter: None Return Value: None */ void KeyEvent_Close(void);4.2 使用范例
先初始化按键事件处理、并注册回调函数和所需的事件
ret += KeyEvent_Init(); // 初始化按键事件处理上下文 /* 设置GPIO_5按键的回调函数，同时需要响应按下，释放以及长按三个事件 */ /* 按键触发顺序： Pressed -> LongPressed(optional) -> Released */ ret += KeyEvent_Connect("GPIO_5", KeyEvent_Callback, KEY_EVENT_PRESSED | KEY_EVENT_LONG_PRESSED | KEY_EVENT_RELEESED);如只需要按下的功能只需要注册KEY_EVENT_PRESSED
ret += KeyEvent_Connect("GPIO_5", KeyEvent_Callback, KEY_EVENT_PRESSED);接着实现KeyEvent_Callback回调
static void KeyEvent_Callback(KEY_ID_TYPE keyid, KEY_EVENT_TYPE event) { printf("[CarDemo] KeyEvent_Callback() : keyid=%d event= %d\n", (int)keyid, (int)event); int ret = -1; switch (keyid) { case KEY_ID_USER: printf("[CarDemo] KEY_ID_USER\n"); if( event == KEY_EVENT_PRESSED ) { /* 按下事件处理代码 */ car_stop(); } if( event == KEY_EVENT_LONG_PRESSED ) { /* 长按事件处理代码 */ } if( event == KEY_EVENT_RELEESED ) { /* 松开事件处理代码 */ } break; case KEY_ID_S1: printf("[CarDemo] KEY_ID_S1\n"); if( event == KEY_EVENT_PRESSED ){ /* 按下事件处理代码 */ car_go_forward(); } if( event == KEY_EVENT_LONG_PRESSED ) { /* 长按事件处理代码 */ car_turn_left(); } if( event == KEY_EVENT_RELEESED ){ /* 松开事件处理代码 */ } break; case KEY_ID_S2: printf("[CarDemo] KEY_ID_S2\n"); if( event == KEY_EVENT_PRESSED ) { /* 按下事件处理代码 */ car_go_back(); } if( event == KEY_EVENT_LONG_PRESSED ) { /* 长按事件处理代码 */ car_turn_right(); } if( event == KEY_EVENT_RELEESED ){ /* 松开事件处理代码 */ } break; default: break; } }5.附上完整的代码如附件car.zip
5.1解压附件将car目录放到applications/sample/wifi-iot/app/下
5.2修改applications/sample/wifi-iot/app/BUILD.gn
import("//build/lite/config/component/lite_component.gni") lite_component("app") { features = [ "car", ] }文章相关附件可以点击下面的原文链接前往下载
https://harmonyos.51cto.com/resource/1286
想了解更多内容，请访问：
和华为官方合作共建的鸿蒙技术社区
https://harmonyos.51cto.com
