I found my issue I think. On the ESP32 I was using large circular buffers, stored in external SPI RAM (128 buffers of 16KB each allocated with calloc()), sending those buffers to fwrite() were causing problems, seems like the SPI RAM access is very slow ? I checked using only 2 buffers located into ...

Thanks for your answer. Does this mean recording audio to SDCard using FATFs is not possible ? Using an oscilloscope, the minimum time I measure to continuously write blocs of 16128 bytes to SD is about 50ms to 70ms (depending on the SD Card) as follow : void mytask() { while(1) { // wait trigger to...

I've implemented circular buffers. It helped a lot but there are still some glitches while recording at 24 bits / 96 Khz. After further analysis, I found the SD card requires about 5ms to write 16KB, and sometimes, it requires up to 1.6sec to write 16KB. Increasing the number of buffers helps but I'...

Hi
I'm facing a similar issue with my SDCArd write speed.
Using high frequency did not help, meaning the problem does not come from the card itself, but from the FATFs implemented in ESP.
Did you find a way to solve that problem ? I need continuous writing without drops while writing.
Thanks
Jerome

Hi
I'm wondering if you found an answer to this ?
I've the same question
Thanks
Jerome

Hi
I'm facing the same issue, did you find a solution to this problem ?
Thanks
Jerome

You are right, I've modified to : char *readBuff; char *writeBuff; // LOOP RECORDING FROM I2S (Run on core 0) xEventGroupSetBits(s_status_event_group, SDCARD_RECORDED_I2S_WRITTEN_BIT); do { i2s_read(I2S_NUM, (void*) readBuff, I2S_DMA_BUFF_LEN_BYTES, &bytes_read, portMAX_DELAY); // wait until write b...

Thanks for your detailed answer Peter. I've separated I2S read from Codec and I2S Write to SDCard on two separated ESP cores. I2S reads continuously the ADC data, store them to a buffer, and once the buffer is full, this core sets a bit in the RTOs event group that triggers writing buffer to the SDc...

Hi My project consists of recording audio from an external ADC to a wave file stored on an SD Card. I allow multiple sampling frequencies among 44.1Khz, 48k and 96k. The external codec is configured in SLAVE mode, so the ESP32 provides MCLK, Bit clock and word clocks. I use APLL in order to achieve ...

Hi All I have to record to a wave file from I2S input coming from an external ADC (es8388 similar to LyraT board). My code works fine up to stereo recording 16 bits at 44.1 KHz. With higher resolution (48K or 96K), a lot of glitches appears in the wave file while recording. I tried using different D...