#include "stm32f10x.h"
/** @addtogroup STM32F10x_StdPeriph_Examples
* @{
*/
/** @addtogroup TIM_7PWM_Output
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
uint16_t TimerPeriod = 0;
uint16_t Channel1Pulse = 0, Channel2Pulse = 0, Channel3Pulse = 0, Channel4Pulse = 0;
/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);
/* Private functions ---------------------------------------------------------*/
/**
* @brief Main program
* @param None
* @retval None
*/
int main(void)
{
/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f10x_xx.s) before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f10x.c file
*/
/* System Clocks Configuration */
RCC_Configuration();
/* GPIO Configuration */
GPIO_Configuration();
/* TIM1 Configuration ---------------------------------------------------
Generate 7 PWM signals with 4 different duty cycles:
TIM1CLK = SystemCoreClock, Prescaler = 0, TIM1 counter clock = SystemCoreClock
SystemCoreClock is set to 72 MHz for Low-density, Medium-density, High-density
and Connectivity line devices and to 24 MHz for Low-Density Value line and
Medium-Density Value line devices
The objective is to generate 7 PWM signal at 17.57 KHz:
- TIM1_Period = (SystemCoreClock / 17570) - 1
The channel 1 and channel 1N duty cycle is set to 50%
The channel 2 and channel 2N duty cycle is set to 37.5%
The channel 3 and channel 3N duty cycle is set to 25%
The channel 4 duty cycle is set to 12.5%
The Timer pulse is calculated as follows:
- ChannelxPulse = DutyCycle * (TIM1_Period - 1) / 100
----------------------------------------------------------------------- */
/* Compute the value to be set in ARR regiter to generate signal frequency at 17.57 Khz */
TimerPeriod = (SystemCoreClock / 17570 ) - 1;
/* Compute CCR1 value to generate a duty cycle at 50% for channel 1 and 1N */
Channel1Pulse = (uint16_t) (((uint32_t) 5 * (TimerPeriod - 1)) / 10);
/* Compute CCR2 value to generate a duty cycle at 37.5% for channel 2 and 2N */
Channel2Pulse = (uint16_t) (((uint32_t) 375 * (TimerPeriod - 1)) / 1000);
/* Compute CCR3 value to generate a duty cycle at 25% for channel 3 and 3N */
Channel3Pulse = (uint16_t) (((uint32_t) 25 * (TimerPeriod - 1)) / 100);
/* Compute CCR4 value to generate a duty cycle at 12.5% for channel 4 */
Channel4Pulse = (uint16_t) (((uint32_t) 125 * (TimerPeriod- 1)) / 1000);
/* 計算周期 時間的方法
TIM_TimeBaseStructure.TIM_Prescaler = 0; //設置用來作為TIM 時鐘頻率除數的預分頻值
那么TIM時鐘就為72M 1/72MHZ=0.01388...us 這就是 系統時間
TimerPeriod = (SystemCoreClock / 17570 ) - 1; //計算中斷周期值
(72MHz/17570) -1=4096.89.. 中斷周期值
4096.89*0.01388=56.8US 這就是實際PWM中斷周期時間
1/56.8US=17.6KHZ 1除以除以周期時間 就是頻率 大約17.6KHz左右。
各個 通道值計算結果。。
Channel1Pulse = 5*（4096-1）/10 =2047 2047*0.01388=28.4US
Channel2Pulse = 375 *(4096 - 1)) / 1000=1535 1535*0.01388=21.3US
Channel3Pulse = 25 * (4096 - 1)) / 100=1023 1023*0.01388=14.19US
Channel4Pulse = 125 *(4096 - 1)) / 1000=511 511*0.01388=7.09US
*/
// //定時器初始化 函數 見庫函數 P246頁
/* Time Base configuration */
TIM_TimeBaseStructure.TIM_Prescaler = 0; //設置用來作為TIM 時鐘頻率除數的預分頻值
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //計數器模式 /* 向上計數模式 */
TIM_TimeBaseStructure.TIM_Period = TimerPeriod;
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //時鐘分割 /* 采樣分頻 */
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0; //設置 周期 計數值
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
//TIM1 配置 見 庫函數 P294 頁
/* Channel 1, 2,3 and 4 Configuration in PWM mode */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //脈沖寬度調制模式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //使能輸出比較狀態
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable; //使能 互補 輸出狀態
TIM_OCInitStructure.TIM_Pulse = Channel1Pulse; //脈沖 值
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //輸出比較極性低
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;//互補 輸出極性高
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set; //MOE=0 設置 TIM1輸出比較空閑狀態
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;//MOE=0 重置 TIM1輸出比較空閑狀態
TIM_OC1Init(TIM1, &TIM_OCInitStructure); //設定好的參數 初始化TIM
TIM_OCInitStructure.TIM_Pulse = Channel2Pulse; //脈寬值
TIM_OC2Init(TIM1, &TIM_OCInitStructure); //設定好的參數 初始化TIM
TIM_OCInitStructure.TIM_Pulse = Channel3Pulse; //脈寬值
TIM_OC3Init(TIM1, &TIM_OCInitStructure); //設定好的參數 初始化TIM
TIM_OCInitStructure.TIM_Pulse = Channel4Pulse; //脈寬值
TIM_OC4Init(TIM1, &TIM_OCInitStructure);//設定好的參數 初始化TIM
/* TIM1 counter enable */
TIM_Cmd(TIM1, ENABLE); //使能 TIM1
/* TIM1 Main Output Enable */
TIM_CtrlPWMOutputs(TIM1, ENABLE); //使能 TIM1 輸出
while (1)
{}
}
/**
* @brief Configures the different system clocks.
* @param None
* @retval None
*/
void RCC_Configuration(void)
{
/* TIM1, GPIOA, GPIOB, GPIOE and AFIO clocks enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOE|
RCC_APB2Periph_GPIOB |RCC_APB2Periph_AFIO, ENABLE);
}
/**
* @brief Configure the TIM1 Pins.
* @param None
* @retval None
*/
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
#ifdef STM32F10X_CL
/* GPIOE Configuration: Channel 1/1N, 2/2N, 3/3N and 4 as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9|GPIO_Pin_11|GPIO_Pin_13|GPIO_Pin_14|
GPIO_Pin_8|GPIO_Pin_10|GPIO_Pin_12;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOE, &GPIO_InitStructure);
/* TIM1 Full remapping pins */
GPIO_PinRemapConfig(GPIO_FullRemap_TIM1, ENABLE);
#else
/* GPIOA Configuration: Channel 1, 2 and 3 as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* GPIOB Configuration: Channel 1N, 2N and 3N as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;
GPIO_Init(GPIOB, &GPIO_InitStructure);
#endif
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
while (1)
{}
}
#endif
/**
* @}
*/
/**
* @}
*/
/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/