怎么利用配置DFSDM滤波器只采集特定频率范围内的音频信号
只想采集20-2000Hz以内的音频信号改怎么配置DFSDM，配置44.1K代码如下：void DFSDM_Init(void){/* Initialize channel 2 */__HAL_DFSDM_CHANNEL_RESET_HANDLE_STATE(&DfsdmChannelHandle);DfsdmChannelHandle.Instance = DFSDM1_Channel2;DfsdmChannelHandle.Init.OutputClock.Activation = ENABLE;DfsdmChannelHandle.Init.OutputClock.Selection = DFSDM_CHANNEL_OUTPUT_CLOCK_AUDIO;DfsdmChannelHandle.Init.OutputClock.Divider = 4; /* 11.294MHz/4 = 2.82MHz */DfsdmChannelHandle.Init.Input.Multiplexer = DFSDM_CHANNEL_EXTERNAL_INPUTS;DfsdmChannelHandle.Init.Input.DataPacking = DFSDM_CHANNEL_STANDARD_MODE; /* N.U. */DfsdmChannelHandle.Init.Input.Pins = DFSDM_CHANNEL_SAME_CHANNEL_PINS;DfsdmChannelHandle.Init.SerialInterface.Type = DFSDM_CHANNEL_SPI_RISING;DfsdmChannelHandle.Init.SerialInterface.SpiClock = DFSDM_CHANNEL_SPI_CLOCK_INTERNAL;DfsdmChannelHandle.Init.Awd.FilterOrder = DFSDM_CHANNEL_FASTSINC_ORDER; /* N.U. */DfsdmChannelHandle.Init.Awd.Oversampling = 10; /* N.U. */DfsdmChannelHandle.Init.Offset = 0;DfsdmChannelHandle.Init.RightBitShift =0;if(HAL_OK != HAL_DFSDM_ChannelInit(&DfsdmChannelHandle)){ Error_Handler();}/* Initialize filter 0 */__HAL_DFSDM_FILTER_RESET_HANDLE_STATE(&DfsdmFilterHandle);DfsdmFilterHandle.Instance = DFSDM1_Filter0;DfsdmFilterHandle.Init.RegularParam.Trigger = DFSDM_FILTER_SW_TRIGGER;DfsdmFilterHandle.Init.RegularParam.FastMode = ENABLE;DfsdmFilterHandle.Init.RegularParam.DmaMode = ENABLE;DfsdmFilterHandle.Init.InjectedParam.Trigger = DFSDM_FILTER_SW_TRIGGER; /* N.U. */DfsdmFilterHandle.Init.InjectedParam.ScanMode = ENABLE; /* N.U. */DfsdmFilterHandle.Init.InjectedParam.DmaMode = DISABLE; /* N.U. */DfsdmFilterHandle.Init.InjectedParam.ExtTrigger = DFSDM_FILTER_EXT_TRIG_TIM1_TRGO; /* N.U. */DfsdmFilterHandle.Init.InjectedParam.ExtTriggerEdge = DFSDM_FILTER_EXT_TRIG_RISING_EDGE; /* N.U. */DfsdmFilterHandle.Init.FilterParam.SincOrder =DFSDM_FILTER_SINC3_ORDER;DfsdmFilterHandle.Init.FilterParam.Oversampling = 64; /* 11.294MHz/(4*64) = 44.1KHz */DfsdmFilterHandle.Init.FilterParam.IntOversampling= 1;if(HAL_OK != HAL_DFSDM_FilterInit(&DfsdmFilterHandle)){ Error_Handler();}/* Configure regular channel and continuous mode for filter 0 */if(HAL_OK != HAL_DFSDM_FilterConfigRegChannel(&DfsdmFilterHandle, DFSDM_CHANNEL_2, DFSDM_CONTINUOUS_CONV_ON)){ Error_Handler();}}没人玩过吗 这是个新东西,楼主可以研究研究，在写个教程 接的数字麦克风么？
不能把 DFSDM 的输出时钟降那么低，否则数字麦克风可能不工作。你想限制带宽的话，DFSDM 采进来降采样之后(比如CKOUT 3.072MHz, 64倍降采样到48kHz PCM)，再自己用软件做FIR低通，再做降采样。 感觉你就是想做个带通滤波器（20~2000Hz），你可以通过软件滤波，或者外部添加带通滤波实现。
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