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定时器 开发板
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下面弄一下定时器，定时器在一个MCU当中还是很重要的。
GD32VF103VX里面包含了4个定时器，最高工作频率可达108M。
发现RGB的3个LED引脚是连在PA1/PA2/PA3正好在tiMER1的CH1/CH2/CH3
上面。
我们先做普通的定时器中断，让红灯每300ms闪烁一次：
void gd_rvstar_timer1_init(void)
{
timer_parameter_struct timer_initpara;
/* ----------------------------------------------------------------------------
TIMER1 Configuration:
TIMER1CLK = SystemCoreClock/54000 = 2KHz.//一个节拍 500us
TIMER1CAR = 600 //载入值600*500us=300ms
---------------------------------------------------------------------------- */
rcu_periph_clock_enable(RCU_TIMER1);
timer_deinit(TIMER1);
timer_update_source_config(TIMER1, TIMER_UPDATE_SRC_REGULAR);
/* initialize TIMER init parameter struct */
timer_struct_para_init(&timer_initpara);
/* TIMER1 configuration */
timer_initpara.prescaler = 53999;
timer_initpara.alignedmode = TIMER_COUNTER_EDGE;
timer_initpara.counterdirection = TIMER_COUNTER_UP;
timer_initpara.period = 600;
timer_initpara.clockdivision = TIMER_CKDIV_DIV1;
timer_init(TIMER1, &timer_initpara);
timer_interrupt_enable(TIMER1, TIMER_INT_UP);
/* Timer Start */
timer_enable(TIMER1);
}
void TIMER1_IRQHandler()
{
uint16_t cnt;
if(SET == timer_interrupt_flag_get(TIMER1, TIMER_INT_FLAG_UP)){
/* clear update interrupt bit */
timer_interrupt_flag_clear(TIMER1, TIMER_INT_FLAG_UP);
/* set led to GREEN */
gd_rvstar_led_off(LED1);
gd_rvstar_led_off(LED2);
gd_rvstar_led_toggle(LED3);
}
}
在面函数里面注册该中断：
ECLIC_Register_IRQ(TIMER1_IRQn, ECLIC_NON_VECTOR_INTERRUPT,
ECLIC_LEVEL_TRIGGER, 3, 0, NULL);
__enable_irq();
编译下载，现象如下：
时间间隔300ms
接下来，我们通过PWM模式控制RGB灯。此时原来定义的普通引脚就不能用了，复用到PWM通道上了。
关闭了定时器的中断，当然，打开也没问题。
修改定时器初始化代码：
void gd_rvstar_timer1_pwm_init(void)
{
timer_parameter_struct timer_initpara;
timer_oc_parameter_struct timer_ocinitpara;
//PWM引脚定义
rcu_periph_clock_enable(RCU_GPIOA);
rcu_periph_clock_enable(RCU_AF);
/*Configure PA1 PA2 PA3(TIMER1 CH1 CH2 CH3) as alternate function*/
gpio_init(GPIOA, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, LEDG_PIN);
gpio_init(GPIOA, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, LEDR_PIN);
gpio_init(GPIOA, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, LEDB_PIN);
/* ----------------------------------------------------------------------------
TIMER2 Configuration:
TIMER1CLK = SystemCoreClock/108 = 1MHz.//一个节拍1us
TIMER1CAR = 1000 //载入值1000*1us=1ms
---------------------------------------------------------------------------- */
rcu_periph_clock_enable(RCU_TIMER1);
timer_deinit(TIMER1);
timer_update_source_config(TIMER1, TIMER_UPDATE_SRC_REGULAR);
/* initialize TIMER init parameter struct */
timer_struct_para_init(&timer_initpara);
/* TIMER1 configuration */
timer_initpara.prescaler = 108-1;
timer_initpara.alignedmode = TIMER_COUNTER_EDGE;
timer_initpara.counterdirection = TIMER_COUNTER_UP;
timer_initpara.period = 255-1;
timer_initpara.clockdivision = TIMER_CKDIV_DIV1;
timer_initpara.repetitioncounter = 0;
timer_init(TIMER1, &timer_initpara);
//timer_interrupt_enable(TIMER1, TIMER_INT_UP);
/* initialize TIMER channel output parameter struct */
timer_channel_output_struct_para_init(&timer_ocinitpara);
/* CH0, CH1 and CH2 configuration in PWM mode */
timer_ocinitpara.outputstate = TIMER_CCX_ENABLE;
timer_ocinitpara.outputnstate = TIMER_CCXN_DISABLE;
timer_ocinitpara.ocpolarity = TIMER_OC_POLARITY_HIGH;
timer_ocinitpara.ocnpolarity = TIMER_OCN_POLARITY_HIGH;
timer_ocinitpara.ocidlestate = TIMER_OC_IDLE_STATE_LOW;
timer_ocinitpara.ocnidlestate = TIMER_OCN_IDLE_STATE_LOW;
timer_channel_output_config(TIMER1,TIMER_CH_1,&timer_ocinitpara);
timer_channel_output_config(TIMER1,TIMER_CH_2,&timer_ocinitpara);
timer_channel_output_config(TIMER1,TIMER_CH_3,&timer_ocinitpara);
/* CH1 configuration in PWM mode0 */
timer_channel_output_pulse_value_config(TIMER1,TIMER_CH_1,255);
timer_channel_output_mode_config(TIMER1,TIMER_CH_1,TIMER_OC_MODE_PWM0);
timer_channel_output_shadow_config(TIMER1,TIMER_CH_1,TIMER_OC_SHADOW_DISABLE);
/* CH2 configuration in PWM mode0 */
timer_channel_output_pulse_value_config(TIMER1,TIMER_CH_2,255);
timer_channel_output_mode_config(TIMER1,TIMER_CH_2,TIMER_OC_MODE_PWM0);
timer_channel_output_shadow_config(TIMER1,TIMER_CH_2,TIMER_OC_SHADOW_DISABLE);
/* CH3 configuration in PWM mode0 */
timer_channel_output_pulse_value_config(TIMER1,TIMER_CH_3,255);
timer_channel_output_mode_config(TIMER1,TIMER_CH_3,TIMER_OC_MODE_PWM0);
timer_channel_output_shadow_config(TIMER1,TIMER_CH_3,TIMER_OC_SHADOW_DISABLE);
/* auto-reload preload enable */
timer_auto_reload_shadow_enable(TIMER1);
/* Timer Start */
timer_enable(TIMER1);
}
void gd_rvstar_rgb_init(int temp1,int temp2,int temp3)
{
/* CH1 duty cycle set */
timer_channel_output_pulse_value_config(TIMER1,TIMER_CH_1,(255-temp2));
/* CH2 duty cycle set */
timer_channel_output_pulse_value_config(TIMER1,TIMER_CH_2,(255-temp1));
/* CH3 duty cycle set */
timer_channel_output_pulse_value_config(TIMER1,TIMER_CH_3,(255-temp3));
}
在main函数里面添加PWM初始化：
gd_rvstar_timer1_pwm_init();
while里面添加：
for(cnt = 255; cnt >=0; cnt--)
{
gd_rvstar_rgb_init(cnt, 0, 0);
delay_1ms(5);
}
for(cnt = 255; cnt >=0; cnt--)
{
gd_rvstar_rgb_init(0, cnt, 0);
delay_1ms(5);
}
for(cnt = 255; cnt >=0; cnt--)
{
gd_rvstar_rgb_init(0, 0, cnt);
delay_1ms(5);
}
编译下载，现象如下：
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回帖（1）
2020-10-19 13:36:08
不错，值得一看
不错，值得一看
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