STM32F103RCTx的PWM输出控制电机
关键功能说明
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PWM配置:
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使用TIM1生成500Hz PWM信号
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输出引脚:PA8 (TIM1_CH1)
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计数器设置:预分频72-1 (1MHz时钟),周期1999 (500Hz)
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初始占空比:50% (CCR=1000)
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按键处理:
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使用TIM2定时器中断实现按键扫描(10ms间隔)
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UP键(PA0):增加占空比
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DOWN键(PA1):减少占空比
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按键消抖:30ms确认按下(3次扫描)
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长按支持:按键保持按下时,每200ms触发一次调整
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工作流程:
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系统初始化后启动PWM输出
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TIM2每10ms触发中断扫描按键状态
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检测到按键按下时设置标志位
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在定时器中断中更新PWM占空比
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主循环处于低功耗状态(HAL_Delay)
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硬件连接
MCU引脚 | 功能 | 连接目标 |
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PA8 | TIM1_CH1 | 电机驱动PWM输入 |
PA0 | GPIO输入 | UP按键(接GND) |
PA1 | GPIO输入 | DOWN按键(接GND) |
GND | 地 | 按键和电机共地 |
功能特点
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精确的PWM控制:
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500Hz PWM频率,适合多数直流电机控制
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占空比范围:0-1999 (0-100%)
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步进调整:10% (200步进值)
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可靠的按键处理:
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定时器中断扫描确保实时性
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30ms消抖时间防止误触发
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支持短按和长按操作
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优化的系统结构:
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中断处理保持主循环简洁
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HAL库提供硬件抽象层
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低功耗设计(主循环使用HAL_Delay)
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使用说明
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在STM32CubeIDE中创建工程
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复制代码到main.c
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配置TIM1为PWM输出,TIM2为基本定时器
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配置PA0和PA1为输入模式
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编译并烧录到STM32F103RC开发板
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按UP/DOWN键调整电机速度
#include "stm32f1xx_hal.h"// 全局变量
TIM_HandleTypeDef htim1;
TIM_HandleTypeDef htim2;
volatile uint16_t pwm_duty = 1000; // 初始占空比50%(ARR=1999)
volatile uint8_t key_up_flag = 0;
volatile uint8_t key_down_flag = 0;// 系统时钟配置
void SystemClock_Config(void) {RCC_OscInitTypeDef osc = {0};RCC_ClkInitTypeDef clk = {0};osc.OscillatorType = RCC_OSCILLATORTYPE_HSE;osc.HSEState = RCC_HSE_ON;osc.PLL.PLLState = RCC_PLL_ON;osc.PLL.PLLSource = RCC_PLLSOURCE_HSE;osc.PLL.PLLMUL = RCC_PLL_MUL9;HAL_RCC_OscConfig(&osc);clk.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;clk.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;clk.AHBCLKDivider = RCC_SYSCLK_DIV1;clk.APB1CLKDivider = RCC_HCLK_DIV2;clk.APB2CLKDivider = RCC_HCLK_DIV1;HAL_RCC_ClockConfig(&clk, FLASH_LATENCY_2);
}// TIM1 PWM初始化 (500Hz)
void MX_TIM1_Init(void) {TIM_ClockConfigTypeDef sClockSourceConfig = {0};TIM_MasterConfigTypeDef sMasterConfig = {0};TIM_OC_InitTypeDef sConfigOC = {0};TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};htim1.Instance = TIM1;htim1.Init.Prescaler = 72 - 1; // 72MHz/72 = 1MHzhtim1.Init.CounterMode = TIM_COUNTERMODE_UP;htim1.Init.Period = 1999; // 1MHz/2000 = 500Hzhtim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;htim1.Init.RepetitionCounter = 0;htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;HAL_TIM_Base_Init(&htim1);sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;HAL_TIM_ConfigClockSource(&htim1, &sClockSourceConfig);HAL_TIM_PWM_Init(&htim1);sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig);sConfigOC.OCMode = TIM_OCMODE_PWM1;sConfigOC.Pulse = pwm_duty;sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_1);sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_DISABLE;sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_DISABLE;sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;sBreakDeadTimeConfig.DeadTime = 0;sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;HAL_TIMEx_ConfigBreakDeadTime(&htim1, &sBreakDeadTimeConfig);// GPIO配置GPIO_InitTypeDef GPIO_InitStruct = {0};__HAL_RCC_GPIOA_CLK_ENABLE();GPIO_InitStruct.Pin = GPIO_PIN_8;GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);// 启动PWMHAL_TIM_PWM_Start(&htim1, TIM_CHANNEL_1);__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, pwm_duty);HAL_TIMEx_PWMN_Start(&htim1, TIM_CHANNEL_1);__HAL_TIM_MOE_ENABLE(&htim1);
}// TIM2 按键扫描定时器初始化 (10ms中断)
void MX_TIM2_Init(void) {htim2.Instance = TIM2;htim2.Init.Prescaler = 7200 - 1; // 72MHz/7200 = 10KHzhtim2.Init.CounterMode = TIM_COUNTERMODE_UP;htim2.Init.Period = 100 - 1; // 10KHz/100 = 100Hz (10ms)htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;HAL_TIM_Base_Init(&htim2);HAL_TIM_Base_Start_IT(&htim2);
}// GPIO初始化
void MX_GPIO_Init(void) {// 按键配置 (PA0, PA1)GPIO_InitTypeDef GPIO_InitStruct = {0};__HAL_RCC_GPIOA_CLK_ENABLE();// UP键 (PA0)GPIO_InitStruct.Pin = GPIO_PIN_0;GPIO_InitStruct.Mode = GPIO_MODE_INPUT;GPIO_InitStruct.Pull = GPIO_PULLUP;HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);// DOWN键 (PA1)GPIO_InitStruct.Pin = GPIO_PIN_1;HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}// 按键扫描函数 (10ms调用一次)
void Key_Scan(void) {static uint8_t up_key_cnt = 0;static uint8_t down_key_cnt = 0;// UP键扫描if (HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0) == GPIO_PIN_RESET) {if (up_key_cnt < 20) up_key_cnt++; // 20*10ms = 200ms消抖+确认if (up_key_cnt == 3) { // 30ms消抖后确认按下key_up_flag = 1;}} else {up_key_cnt = 0;}// DOWN键扫描if (HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_1) == GPIO_PIN_RESET) {if (down_key_cnt < 20) down_key_cnt++;if (down_key_cnt == 3) {key_down_flag = 1;}} else {down_key_cnt = 0;}
}// 定时器中断回调
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) {if (htim->Instance == TIM2) {Key_Scan(); // 每10ms扫描一次按键// 处理UP键if (key_up_flag) {if (pwm_duty < 1900) pwm_duty += 100; // 增加10%占空比__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, pwm_duty);key_up_flag = 0;}// 处理DOWN键if (key_down_flag) {if (pwm_duty > 100) pwm_duty -= 100; // 减少10%占空比__HAL_TIM_SET_COMPARE(&htim1, TIM_CHANNEL_1, pwm_duty);key_down_flag = 0;}}
}int main(void) {HAL_Init();SystemClock_Config();MX_GPIO_Init();MX_TIM1_Init();MX_TIM2_Init();while (1) {// 主循环可添加其他任务HAL_Delay(100);}
}// 中断处理函数
void TIM2_IRQHandler(void) {HAL_TIM_IRQHandler(&htim2);
}