如何实现在STMT/8L-EV1上发出蜂鸣声

你好
 
 
 “我有STMT / 8L-EV1，我想产生4KHz的哔哔声”
 ''我已经尝试将PWM用于TIM1_Channel2，蜂鸣器已开启，但这也无效。''
 IO引脚可能没有足够的驱动器直接驱动蜂鸣器。你需要一个晶体管或某种驱动放大器。
 
 “我不想把哔哔声挂在计时器上”
 仅使用代码很难获得常规的开/关时段。使用定时器（在PWM模式下）更容易。
 
 如果你不介意STM8被捆绑只是切换IO端口，那么就可以完成。



以下为原文





Hi


''I have the STMT/8L-EV1 and I'd like to generate a 4KHz beep sound''
''I've tried to use the PWM for the TIM1_Channel2 the buzzer is on but that didn't work either.''
The IO pin probably does not have enough drive to drive the buzzer directly. You will needs a transistor or some kind of driver amp.

'' I don't want the beep tied to a timer''
Very difficult to get a regular on/off period just using code. It is easier to use the timer (in PWM mode) to do this.

If you do not mind the STM8 being tied up just toggling the IO port then it can be done.

我懂了。
 
 
我仔细查看了评估板的演示代码，发现了两个打开和关闭PWM的功能。但是，我在我自己的代码中调用这些函数，它们不起作用。有什么想法吗？
 
void PlayPWM（u16 freq）
{
 u16责任周期;
 
 
 if（freq！= 0）
 {
 / *设定频率* /
 TIM1-> ARRH =（u8）（freq> 8）;
 TIM1-> ARRL =（u8）（freq）;
 / *设置占空比= freq / 2 = 50％* /
 dutycycle =（u16）（freq＆gt;＆gt; 4）;
 TIM1-> CCR2H =（u8）（占空比> 8）;
 TIM1-> CCR2L =（u8）（占空比）;
 / *启用OCN2 * /
 TIM1-> CCER1 | = 0x40;
 }
}
 
 
void StopPWM（void）
{
 / *禁用OCN2 * /
 TIM1-> CCER1＆amp; =（u8）（~0x40）;
}



以下为原文





I see.


I've looked through the demo code from the eval board and found this, two functions to turn the PWM on and off.  However I go and call these functions in my own code, they do not work.  Any thoughts?


void PlayPWM(u16 freq)

{

  u16 dutycycle;







  if (freq != 0)

  {

    /* Set frequency */

    TIM1->ARRH = (u8)(freq >> 8);

    TIM1->ARRL = (u8)(freq);

    /* Set duty cycle = freq/2 = 50% */

    dutycycle = (u16)(freq >> 4);

    TIM1->CCR2H = (u8)(dutycycle >> 8);

    TIM1->CCR2L = (u8)(dutycycle);

    /* Enable OCN2 */

    TIM1->CCER1 |= 0x40;

  }

}







void StopPWM(void)

{

  /* Disable OCN2 */

  TIM1->CCER1 &= (u8)(~0x40);

}

你好
 
 
 我不熟悉STM8，因为我使用的是STM32F4系列。
 
 您是否已将IO引脚配置为输出定时器输出而不是
 IO？



以下为原文





Hi


I am no familiar with the STM8 because I work with STM32F4 series.

Have you configured the IO pin to output the timer output instead of  
IO ?

初始化和配置引脚的功能是
 
 GPIO_Init（GPIOE，GPIO_Pin_1，GPIO_Mode_Out_PP_Low_Fast）;
 
 
我不知道，或者还没有找到一种方法来配置实际的定时器引脚。



以下为原文





The function to initialize and configure the pin is

GPIO_Init(GPIOE, GPIO_Pin_1, GPIO_Mode_Out_PP_Low_Fast);


I don't know, or haven't found a way to configure the actual pin to the timer.

您是否查看了所用设备的参考手册？
 
 
 ''备用功能输出提供从外设到输出或I / O焊盘的直接路径，优先于数据输出锁存寄存器（Px_ODR）中的端口位，并强制Px_DDR对应位为1.备用功能输出可以是推挽式或伪开漏式，具体取决于外设和控制寄存器1（Px_CR1），并且可以根据控制寄存器2（Px_CR2）值控制斜率。



以下为原文





Have you checked the reference manual for the device you are using?


''Alternate function outputs provide a direct path from a peripheral to an output or to an I/O pad, taking precedence over the port bit in the data output latch register (Px_ODR) and forcing the Px_DDR corresponding bit to 1. An alternate function output can be push-pull or pseudo-open drain depending on the peripheral and Control register 1 (Px_CR1) and slope can be controlled depending on the Control register 2 (Px_CR2) values.''