• I2S
  • Intermediate
  • 5 min
  • Serial CLI

Recipe · Intermediate · I2S

How to record an I2S microphone signal

Use I2S record and test mic to check microphone signal strength and visualize input activity.

I2S audio signal between microphone and speaker.
A practical ESP32 Bit Pirate workflow based on the documented firmware commands.
Step 1

Commands

Run the workflow from the CLI after selecting the matching mode.

Result

What it means

The output confirms that the protocol path is working and gives you a baseline for deeper experiments.

Troubleshooting

  • Check DATA direction: microphone data must go to the ESP32 input.
  • Confirm BCLK and LRCK pins from config.
  • Try test mic before interpreting record visualization.

Next steps

  • Compare silence and sound levels.
  • Use reset before switching back to output mode.
  • Capture clocks with a logic analyzer if the mic stays silent.

I2S microphone recording FAQ

What does I2S record show?

It records and visualizes microphone input activity so you can confirm that the digital mic is producing samples and reacting to sound.

What kind of microphone is this recipe for?

This workflow is for digital I2S microphones that provide sample data over BCLK, LRCK and DATA. Analog electret modules need an ADC-style workflow instead of the I2S recorder.

Should I run test mic before record?

Yes. test mic gives a quick signal-strength check before you interpret the longer record visualization or compare silence versus sound.

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