STM32芯片跑马灯实验pc8-15推挽输出2兆 奇数灯先亮 (流水灯)偶数后亮寄存器代码
时间: 2024-10-20 19:17:16 浏览: 43
03、STM32-F4 直流无刷电机-串口控制 HAL库源代码
STM32芯片的跑马灯实验通常涉及GPIO口的推挽输出控制LED灯,PC8-15表示这组引脚用于驱动LED,实现2MHz(即每秒200万次)的流水灯效果,奇数灯先行点亮,然后偶数灯依次亮起。
首先,你需要配置STM32的GPIO口PC8-15为推挽输出模式,这样可以驱动LED。你可以通过以下步骤操作:
1. **初始化GPIO**:
- 设置PC8-15的GPIO口为输出模式,并设置初始状态为高电平(关闭LED)。
```c
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11; // PC8-15
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; // Push-Pull output mode
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; // Set speed to max for your board
HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);
```
2. **定时器控制**:
使用STM32的定时器来精确地控制LED点亮和熄灭的时间。例如,你可以用TIM2定时器,周期设为半个LED点亮周期(大约500us),并设置溢出中断来触发LED切换。
```c
TIM_TimeBaseInitTypeDef.TIM_TimeBaseStructure;
TIM_TimeBaseInitTypeDef TIM_InitStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_InitStructure.TIM_Period = 500; // 500 us period, depends on desired speed
TIM_InitStructure.TIM_Prescaler = RCC_GetClockFreq(RCC_HCLK) / 4 / 1000000 - 1; // Calculate based on CPU clock frequency
HAL_TIM_TimeBaseInit(TIM2, &TIM_InitStructure);
TIM_OCInitStructure.TIM_OutputState = TIM_OCPulseActiveHigh; // Active High output state
TIM_OCInitStructure.TIM_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11; // Same pins as GPIO
TIM_OCInitStructure.TIM_OutputType = TIM_OCPolarity_ActiveLow; // Pulse low for LED off
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; // Active Low pulse
HAL_TIM_OCInit(TIM2, &TIM_OCInitStructure);
HAL_NVIC_EnableIRQ(TIM2_IRQn); // Enable interrupt for timer
// Register the interrupt service routine (ISR)
static void TIM2_IRQHandler(void) {
HAL_TIM_IRQHandler(&htim2);
// Swap LED states (odd -> even or vice versa) when timer overflows
}
```
3. **灯的状态管理**:
在`TIM2_IRQHandler`中,你可以根据计数器是否达到奇数或偶数值来改变LED的状态。
```c
volatile uint16_t counter = 0;
void TIM2_IRQHandler() {
if (counter % 2 == 1) { // If odd number
// Turn off all LEDs and prepare to turn on next odd one
HAL_GPIO_ToggleBits(GPIOB, GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11);
} else { // Even number
// Same as above but for even LEDs
}
++counter; // Increment counter for the next step
}
```
注意:这个例子假设你已经连接了LED灯到正确的GPIO引脚,并且你的STM32板子支持所需频率的定时器。请根据实际硬件调整相关的定时器配置。
阅读全文