STM32 Discovery, RC Receiver, PWM Input

[benjamin-chia]

Posted on February 21, 2014 at 08:59

/* Includes ------------------------------------------------------------------*/
#include ''stm32f4xx.h''
#include ''stm32f4xx_syscfg.h''
#include ''stm32f4xx_rcc.h''
#include ''stm32f4xx_gpio.h''
#include ''stm32f4xx_exti.h''
#include ''misc.h''
/** @addtogroup STM32F4_Discovery_Peripheral_Examples
* @{
*/
/** @addtogroup EXTI
* @{
*/
/* Private typedef -----------------------------------------------------------*/
EXTI_InitTypeDef EXTI_InitStructure;
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
void EXTILine0_Config(void);
void LEDInit(void);
int ch10;
/* Private functions ---------------------------------------------------------*/
/**
* @brief EXTI Example program
* @param None
* @retval None
*/
int initdelete3(void){
/* Initialize LED4 mounted on STM32F4-Discovery board */
LEDInit();
/* Configure EXTI Line0 (connected to PA0 pin) in interrupt mode */
EXTILine0_Config();
return 0;
}
void delete3(void)
{
/* Generate software interrupt: simulate a rising edge applied on EXTI0 line */
//EXTI_GenerateSWInterrupt(EXTI_Line0);
//while (1)
__NOP();
}
/**
* @brief Configures LED GPIO.
* @param None
* @retval None
*/
void LEDInit()
{
GPIO_InitTypeDef GPIO_InitStructure;
/* Enable the GPIO_LED Clock */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
/* Configure the GPIO_LED pin */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure);
}
/**
* @brief Configures EXTI Line0 (connected to PA0 pin) in interrupt mode
* @param None
* @retval None
*/
void EXTILine0_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
/* Enable GPIOA clock */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
/* Enable SYSCFG clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
/* TIM5 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5, ENABLE);
/* Time base configuration - SystemCoreClock = 168000000 for 168 MHz board ABP1 @ 42 MHz (DIV4) */
TIM_TimeBaseStructure.TIM_Prescaler =(uint16_t) (((SystemCoreClock / 1000000) / 2) - 1); // Shooting for 1 MHz, (1us)
TIM_TimeBaseStructure.TIM_Period = 10000 - 1; ////0xFFFF; // Maximal
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM5, &TIM_TimeBaseStructure);
/* TIM enable counter */
TIM_Cmd(TIM5, ENABLE);
/* Configure PA0 pin as input floating */
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* Connect EXTI Line0 to PA0 pin */
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource0);
/* Configure EXTI Line0 */
EXTI_InitStructure.EXTI_Line = EXTI_Line0;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
/* Enable and set EXTI Line0 Interrupt to the lowest priority */
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/**
* @brief This function handles External line 0 interrupt request.
* @param None
* @retval None
*/
void EXTI0_IRQHandler(void)
{
if(EXTI_GetITStatus(EXTI_Line0) != RESET)
{
/* Toggle LED1 */
GPIO_ToggleBits(GPIOD, GPIO_Pin_13);
ch10 = TIM_GetCounter(TIM5);
/* Clear the EXTI line 0 pending bit */
EXTI_ClearITPendingBit(EXTI_Line0);
}
}