[经验]

【星空派GD32F303开发板试用体验】-02-PWM实验之GRB三色灯模块

许小啵

2021-10-31 12:24:05

4834 开发板试用

RGB紫色呼吸灯

PWM又称脉冲宽度调制，是学习掌握单片机外设的基本功能之一，对于温度调节，电机控制，等场景中使用较多。星空派手册资料详细介绍了PWM的原理和使用方法，根据官方提供的例程做了简单修改通过两路PWM波控制调节出紫色呼吸灯效果和6种颜色的灯光进行循环显示。通过此实验进一步加深了对gd32单片机PWM功能的学习。

首先利用单片机的PA8和PB0两个IO口进行复用成定时器PWM模式，通过两组PWM波同时工作可以兑出RGB灯的任意颜色，在通过官方提供的库进行基础配置，最后设置定时器的频率和占空比，在主函数里进行对占空比这个变量的调节，就可以实现呼吸灯的效果，此实验较为简单根据官方提供代码简单修改就可以实现本次效果。

#define __tiMER_PWM_C__
#include
/**
设置引脚为PWM模式
*/
void gpio_pwm_config(void)
{
rcu_periph_clock_enable(RCU_GPIOA);
rcu_periph_clock_enable(RCU_GPIOB);
gpio_init(GPIOA, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_8);
gpio_init(GPIOB, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_0);
}
/**
brief configure the TIMER peripheral
param[in] none
param[out] none
retval none
*/
//120MHz
void timer_pwm_config(void)
{
/* TIMER0 configuration: generate PWM signals with different duty cycles:
TIMER0CLK = SystemCoreClock / 120 = 1MHz */
timer_oc_parameter_struct timer_ocintpara;
timer_parameter_struct timer_initpara;
gpio_pwm_config();
rcu_periph_clock_enable(RCU_TIMER2);
rcu_periph_clock_enable(RCU_TIMER0);
rcu_periph_clock_enable(RCU_AF);
timer_deinit(TIMER0);
timer_deinit(TIMER2);
/* TIMER0 configuration */
//预分频 119
timer_initpara.prescaler = 119;
//边沿触发
timer_initpara.alignedmode = TIMER_COUNTER_EDGE;
timer_initpara.counterdirection = TIMER_COUNTER_UP;
//装载值 500 CAR
timer_initpara.period = 500;
timer_initpara.clockdivision = TIMER_CKDIV_DIV1;
timer_initpara.repetitioncounter = 0;
timer_init(TIMER0,&timer_initpara);
timer_init(TIMER2,&timer_initpara);
/* CH0 configuration in PWM mode */
//使能通道输出
timer_ocintpara.outputstate = TIMER_CCX_ENABLE;
//不需要通道互补
timer_ocintpara.outputnstate = TIMER_CCXN_DISABLE;
//通道输出极性为高电平
timer_ocintpara.ocpolarity = TIMER_OC_POLARITY_HIGH;
//通道互补输出极性高电平
timer_ocintpara.ocnpolarity = TIMER_OCN_POLARITY_HIGH;
//通道输出空闲状态低电平
timer_ocintpara.ocidlestate = TIMER_OC_IDLE_STATE_LOW;
//通道互补输出空闲状态低电平
timer_ocintpara.ocnidlestate = TIMER_OCN_IDLE_STATE_LOW;
timer_channel_output_config(TIMER2,TIMER_CH_2,&timer_ocintpara);
timer_channel_output_config(TIMER0,TIMER_CH_0,&timer_ocintpara);
//配置TIMER通道输出脉冲值也就是 CHX_CV值
timer_channel_output_pulse_value_config(TIMER2,TIMER_CH_2,250);
timer_channel_output_pulse_value_config(TIMER0,TIMER_CH_0,250);
//设置定时器通道0输出为PWM模式
timer_channel_output_mode_config(TIMER2,TIMER_CH_2,TIMER_OC_MODE_PWM0);
timer_channel_output_shadow_config(TIMER2,TIMER_CH_2,TIMER_OC_SHADOW_DISABLE);
timer_channel_output_mode_config(TIMER0,TIMER_CH_0,TIMER_OC_MODE_PWM0);
timer_channel_output_shadow_config(TIMER0,TIMER_CH_0,TIMER_OC_SHADOW_DISABLE);
timer_primary_output_config(TIMER0,ENABLE);
timer_primary_output_config(TIMER2,ENABLE);
/* auto-reload preload enable */
timer_auto_reload_shadow_enable(TIMER2);
timer_auto_reload_shadow_enable(TIMER0);
timer_enable(TIMER2);
timer_enable(TIMER0);
}
#include "gd32f30x.h"

#include "gd32f303e_eval.h"

#include "systick.h"

#include "timer_pwm.h"

int main(void)

{

int16_t i = 0;

FlagStatus breathe_flag = SET;

/* configure the TIMER peripheral */

timer_pwm_config();

/* configure systick */

systick_config();

while (1){

      /* delay a time in milliseconds */

      delay_1ms(40);

      if (SET == breathe_flag){

         i = i + 10;

      }else{

         i = i - 10;

      }

      if(500 < i){

         breathe_flag = RESET;



      }

      if(0 >= i){

         breathe_flag = SET;

      }

      //配置TIMER通道输出脉冲值也就是 CHX_CV值

      timer_channel_output_pulse_value_config(TIMER2,TIMER_CH_2,i);

                              timer_channel_output_pulse_value_config(TIMER0,TIMER_CH_0,i);

}

}