99 lines
3.0 KiB
C
99 lines
3.0 KiB
C
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/***
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***************************************************************************
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* @file lcd_pwm.c
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* @brief 定时器初始化，配置pwm,作为LCD的背光调节,若PWM背光引脚改变，除了需要修改相关的宏外，
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* 还需要把下面三个函数改成相应通道的函数 ：
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* TIM_OC2Init();
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* TIM_OC2PreloadConfig();
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* TIM_SetCompare2();
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******************************************************************************
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*
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*
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*
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*
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***************************************************************************
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***/
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#include "lcd_pwm.h"
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static u16 LCD_PwmPeriod = 500; //定时器重载值
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static u32 LCD_PwmPrescaler = 90 - 1; //定时器分频值
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static u8 g_pulse=100;
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// 函数：TIM4 PWM CH2 IO口初始化
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//
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void LCD_PWM_GPIO(void)
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{
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GPIO_InitTypeDef GPIO_InitStructure;
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//IO口时钟配置
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RCC_AHB1PeriphClockCmd (LCD_PWM_CLK, ENABLE);
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//IO引脚复用
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GPIO_PinAFConfig(LCD_PWM_PORT,LCD_PWM_PinSource,LCD_PWM_AF);
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//IO配置
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GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
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GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽
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GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
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GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; //速度
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//初始化 TIM4_CH2 引脚
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GPIO_InitStructure.GPIO_Pin = LCD_PWM_PIN;
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GPIO_Init(LCD_PWM_PORT, &GPIO_InitStructure);
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}
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// 函数：LCD PWM 占空比设置
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// 参数：pulse - 占空比，范围 0-100
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//
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void LCD_PwmSetPulse (u8 pulse)
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{
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u16 compareValue ;
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g_pulse=pulse;
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compareValue = pulse * LCD_PwmPeriod / 100; //根据占空比设置比较值
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TIM_SetCompare2(LCD_TIM,compareValue);
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}
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//获取屏幕亮度
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u8 LCD_PwmGetPulse (void)
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{
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return g_pulse;
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}
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// 函数：LCD PWM 初始化
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// 参数： pulse - LCD背光占空比
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// 说明：LCD背光的PWM频率固定为10KHz
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//
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void LCD_PWMinit(u8 pulse)
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{
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TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
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TIM_OCInitTypeDef TIM_OCInitStructure;
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g_pulse=pulse;
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LCD_PWM_GPIO (); //初始化IO口
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RCC_APB1PeriphClockCmd(LCD_TIM_CLK,ENABLE); ///使能时钟
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//定时器基本设置
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TIM_TimeBaseInitStructure.TIM_Period = LCD_PwmPeriod; //重载值
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TIM_TimeBaseInitStructure.TIM_Prescaler= LCD_PwmPrescaler; //分频系数
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TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数
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TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
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TIM_TimeBaseInit(LCD_TIM,&TIM_TimeBaseInitStructure);//初始化
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//PWM输出配置
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TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //PWM模式1
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TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //使能比较输出
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TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; // 小于跳变值输出高电平
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TIM_OC2Init(LCD_TIM, &TIM_OCInitStructure); //初始化定时器比较输出通道 2
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TIM_OC2PreloadConfig(LCD_TIM, TIM_OCPreload_Enable); //自动重载比较输出通道 2 的值
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TIM_ARRPreloadConfig(LCD_TIM,ENABLE);//使能自动重载
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TIM_Cmd(TIM4,ENABLE); //使能定时器
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LCD_PwmSetPulse (pulse); //设置占空比
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}
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