2018-09-14 10:38 PM
Hi, I am using stm32f411 discovery board with i2s mems microphone, I am using hal library and pdm2pcm librray, I have referred to audio record and play back examples, application notes, and I still have the following questions:
hi2s2.Init.Standard = I2S_STANDARD_LSB;
hi2s2.Init.DataFormat = I2S_DATAFORMAT_16B;
hi2s2.Init.AudioFreq = 2*(I2S_AUDIOFREQ_48K);
PDM_FilterHandler.bit_order = PDM_FILTER_BIT_ORDER_LSB;
PDM_FilterHandler.endianness = PDM_FILTER_ENDIANNESS_LE;
PDM_FilterHandler.high_pass_tap =2122358088;
PDM_FilterHandler.out_ptr_channels = 1;
PDM_FilterHandler.in_ptr_channels = 1;
PDM_FilterConfig.output_samples_number = 16;
PDM_FilterConfig.mic_gain = 24;
PDM_FilterConfig.decimation_factor = PDM_FILTER_DEC_FACTOR_64;
PDM_BUFF_SIZE 128
PCM_OUT_SIZE 16