Hi Simona, SD Cards have busy time times of 500ms max (per spec) for saving data internally. I saw SD Cards taking over a second of busy time.
You can check with the Oszilloskop. I think data0 is the pin that signalize busy... Per design, you need a stream buffer that can handle your audio stream up to 500ms... Regards, Simon -- Ingenieurbüro-Filgis USt-IdNr.: DE305343278 -- sent by mobile phone Alan C. Assis <acas...@gmail.com> schrieb am Do., 19. Okt. 2023, 23:36: > Hi Simona, > > On 10/19/23, Simona Toaca <simona.alexandra2...@gmail.com> wrote: > > Hello, > > I am trying to record audio using a MEMS microphone, but the final > > recording is missing parts periodically (for example, with a sample rate > of > > 8kHz, there are parts ~1s long missing once every ~10-11s. Using a sample > > rate of 48kHz, the period is ~1s long). This is my first time working > with > > I2S and I can't figure out what causes this behaviour. > > > > My setup is as follows: > > - the microphone has 24-bit depth in a 32-bit word (MSB first) when > > transmitting data > > - i am using nxrecorder to record the pcm audio onto an SD card (device > > pcm_in0) > > - to listen to the recording i import the file into Audacity (24-bit, Big > > Endian) > > > > Defconfig regarding audio: > > CONFIG_AUDIO=y > > CONFIG_AUDIO_BUFFER_NUMBYTES=6144 (from the i2s buffer which is 8192 > bytes, > > 3/4 of it is "useful" info, 6144 bytes in total) > > CONFIG_AUDIO_DMA=y > > CONFIG_AUDIO_FORMAT_RAW=y > > CONFIG_AUDIO_I2S=y > > CONFIG_DMA=y > > CONFIG_DMA_LINK=y > > CONFIG_DRIVERS_AUDIO=y > > CONFIG_ESP32_I2S0=y > > CONFIG_ESP32_I2S0_BCLKPIN=25 > > CONFIG_ESP32_I2S0_DATA_BIT_WIDTH_24BIT=y > > CONFIG_ESP32_I2S0_DINPIN=26 > > CONFIG_ESP32_I2S0_SAMPLE_RATE=8000 > > CONFIG_ESP32_I2S0_WSPIN=27 > > CONFIG_ESP32_I2S=y > > CONFIG_I2S_DMADESC_NUM=4 > > > > I tried modifying the number of audio buffers and also making them > bigger, > > but that did not solve the problem. > > Any ideas on what could cause this? > > > > Could it be something related to SDCard storage? Maybe it needs some > optimization! > > Please try using a RAMDISK of 1MB+ and save the file to it. > > If it works we will know the SDCard could be the limitation of this > configuration. > > BR, > > Alan >
