Electrical – [STM32F103RB][C] – DMA, can’t change PWM period

cdmapwmstm32

Hello i woul'd like change PWM period with DMA. I wrote code but i don't know why LED BLINKING with constant time

#include "stm32f10x.h"
#include "stm32f1xx_nucleo.h"
#include "stm32f10x.h"

int i =0;
u16 PWM_Buf[198];

void TIMInit(void);
void GPIOInit(void);
void DMAInit(void);
void PWMInit(void);

int main(void)
{
 GPIOInit();
 TIMInit();
 DMAInit();
 PWMInit();

 for(i = 0;i<198;i++)
 {
  PWM_Buf[i] = i * 10; // <-------- VALUE OF TIM PERIOD
 }


    while(1)
    {
    }
}
void TIMInit(void)
{
 TIM_TimeBaseInitTypeDef TIMInit;

 RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

    TIMInit.TIM_Period = 1000;
    TIMInit.TIM_Prescaler = 64000;

    TIMInit.TIM_ClockDivision = TIM_CKD_DIV1;
    TIMInit.TIM_CounterMode = TIM_CounterMode_Up;

    TIMInit.TIM_RepetitionCounter = 200;

    TIM_TimeBaseInit(TIM1, &TIMInit);
}

void GPIOInit(void)
{
  GPIO_InitTypeDef GPIOInit;

 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
 RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);

   GPIOInit.GPIO_Pin = GPIO_Pin_8;
   GPIOInit.GPIO_Mode = GPIO_Mode_AF_PP;
   GPIOInit.GPIO_Speed = GPIO_Speed_50MHz;

   GPIO_Init(GPIOA, &GPIOInit);
}

void DMAInit(void)
{
 #define TIM1_ARR_Address 0X40012C2C

 DMA_InitTypeDef DMAInit;

 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
 DMA_DeInit(DMA1_Channel5);
 DMAInit.DMA_PeripheralBaseAddr = (u16)TIM1_ARR_Address;
 DMAInit.DMA_MemoryBaseAddr = (u32)PWM_Buf;
 DMAInit.DMA_DIR = DMA_DIR_PeripheralDST;
 DMAInit.DMA_BufferSize = 198;
 DMAInit.DMA_PeripheralInc = DMA_PeripheralInc_Enable;
 DMAInit.DMA_MemoryInc = DMA_MemoryInc_Enable;
 DMAInit.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
 DMAInit.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
 DMAInit.DMA_Mode = DMA_Mode_Circular;
 DMAInit.DMA_Priority = DMA_Priority_High;
 DMAInit.DMA_M2M = DMA_M2M_Disable;

 DMA_Init(DMA1_Channel5, &DMAInit);

    DMA_Cmd(DMA1_Channel5, ENABLE);
}

void PWMInit(void)
{
 TIM_OCInitTypeDef  PWMInit;

    PWMInit.TIM_OCMode = TIM_OCMode_PWM1;
    PWMInit.TIM_OutputState = TIM_OutputState_Enable;
    PWMInit.TIM_Pulse = 500;
    PWMInit.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(TIM1, &PWMInit);
    TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);
    TIM_ARRPreloadConfig(TIM1, ENABLE);
    TIM_DMACmd(TIM1, TIM_DMA_Update, ENABLE);
    TIM_Cmd(TIM1, ENABLE);
    TIM_CtrlPWMOutputs(TIM1, ENABLE);
}

Best Answer

DMAInit.DMA_PeripheralBaseAddr = (u16)TIM1_ARR_Address;  

You can't cast a pointer as an unsigned 16 bit. Pointers are 32 bit on this platform.
Like this: (uint32_t)&TIM1->ARR.

DMAInit.DMA_PeripheralInc = DMA_PeripheralInc_Enable;

You can't increment the peripheral address, the next cycle would be TIMx_RCR, then TIMx_CCR1 etc.