Posted on December 17, 2015 at 19:59
Hi,
I am trying to get a PWM Signal out of my discovery board but I must be missing something. I started with a writingthe registers directly, then I tried it with the peripheral library. Ilooked at various examples but I cannot find my problem. The timer is running, I can toggle the pin...Please somebody help me, I am going crazy! Here is the code.
Best regards,
Christian
#include ''stm32f0xx.h''
#include ''stm32f0xx_gpio.h''
#include ''stm32f0xx_rcc.h''
#include ''stm32f0xx_tim.h''
#include ''system_stm32f0xx.h''
void
main(
void
)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
uint16_t period;
uint16_t pulse;
SystemInit();
period = 0xFF;
pulse = period >> 1;
/* GPIOA clock enable */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
/* Initialize PA8, Alternative Function, 50Mhz, Output, Push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_Level_3;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_0);
/* TIM1 clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 , ENABLE);
/* Timer Base configuration */
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_Period = period;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
/* Channel 1 output configuration */
TIM_OCStructInit(&TIM_OCInitStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = pulse;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
/* Enable Preload register on CCR1. */
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);
/* TIM1 counter enable */
TIM_Cmd(TIM1, ENABLE);
/* TIM1 Main Output Enable */
TIM_CtrlPWMOutputs(TIM1, ENABLE);
/* forever... */
while
(1)
{
__asm(
''nop''
);
}
}
