Posted on December 03, 2011 at 10:50I want to create fading Led with pwm, but my code doesn't works. If I simply set bit 1 to pin my led is lights.Please help me.
I'm use stm32f103vet6.
int main(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
TIM_OCInitTypeDef TIM_OCInitStruct;
RCC_APB2PeriphClockCmd(
RCC_APB2Periph_GPIOB |
RCC_APB2Periph_AFIO, ENABLE );
RCC_APB1PeriphClockCmd( RCC_APB1Periph_TIM3, ENABLE );
// Set the Vector Table base address at 0x08000000.
NVIC_SetVectorTable( NVIC_VectTab_FLASH, 0x0 );
NVIC_PriorityGroupConfig( NVIC_PriorityGroup_4 );
// Configure HCLK clock as SysTick clock source.
SysTick_CLKSourceConfig( SysTick_CLKSource_HCLK );
GPIO_StructInit(&GPIO_InitStructure); // Reset init structure
// Setup Blue LED on STM32-Discovery Board to use PWM.
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; // Alt Function - Push Pull
GPIO_Init( GPIOB, &GPIO_InitStructure );
GPIO_PinRemapConfig( GPIO_FullRemap_TIM3, ENABLE ); // Map TIM3_CH3 to GPIOC.Pin8
// Let PWM frequency equal 100Hz.
// Let period equal 1000. Therefore, timer runs from zero to 1000. Gives 0.1Hz resolution.
// Solving for prescaler gives 240.
TIM_TimeBaseStructInit( &TIM_TimeBaseInitStruct );
TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV4;
TIM_TimeBaseInitStruct.TIM_Period = 1000 - 1; // 0..999
TIM_TimeBaseInitStruct.TIM_Prescaler = 240 - 1; // Div 240
TIM_TimeBaseInit( TIM3, &TIM_TimeBaseInitStruct );
TIM_OCStructInit( &TIM_OCInitStruct );
TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1;
// Initial duty cycle equals 0%. Value can range from zero to 1000.
TIM_OCInitStruct.TIM_Pulse = 999; // 0 .. 1000 (0=Always Off, 1000=Always On)
TIM_OC3Init( TIM3, &TIM_OCInitStruct );
TIM_UpdateDisableConfig(TIM3,ENABLE);
TIM_Cmd( TIM3, ENABLE );
while (1);
}
#pwm #led #stm32 #stm32f103
