求助！STM32F103利用DMA控制PWM占空比出现错误

只看该作者 · 2016-12-23 10:33

本帖最后由 Crashdown 于 2016-12-26 10:05 编辑

新手求助，我想用DMA控制PWM占空比以控制舵机转动，在占空比减少的情况下没有问题，可是在占空比累加的情况下只会输出最后一个数据，增加每两个数据之间的差值情况会有所好转，但是还是会存在一定问题，请问是什么原因？

测试数据：
累加：300,309,319,328,338,348,357,367,376,386,396,405,415,424,434,444,453,463,472,482,492,501,511,520,530,540,549,559,568,578,588,597,607,616,626,636,645,655,664,674,684,693,703,712,722,732,741,751,760,770,

累减：780,770,760,751,741,732,722,712,703,693,684,674,664,655,645,636,626,616,607,597,588,578,568,559,549,540,530,520,511,501,492,482,472,463,453,444,434,424,415,405,396,386,376,367,357,348,338,328,319,309,

程序配置：
DMA_Config(uint_16t* action_buf, uint_16t action_size) {
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, input_state);

  DMA_InitTypeDef DMA_InitStructure;
  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)action_buf;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
  DMA_InitStructure.DMA_BufferSize = action_size;
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
  DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
  DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;
  DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
  DMA_InitStructure.DMA_PeripheralBaseAddr = TIM1_BASE + 0x34;
  DMA_Init(DMA1_Channel3, &DMA_InitStructure);
  DMA_ITConfig(DMA1_Channel3, DMA_IT_TC, ENABLE);
  TIM_DMACmd(TIM1, TIM_DMA_CC1, ENABLE);
  DMA_Cmd(DMA1_Channel3, ENABLE);
}