MEMS PDM Microphone Data Acquisition with Raspberry Pi Pico

Overview

This repository contains code for reading raw data from a MEMS PDM (Pulse Density Modulation) microphone using a Raspberry Pi Pico microcontroller. The raw data obtained from the microphone is transmitted over serial communication using USB CDC (Communications Device Class) protocol. This project is particularly useful for testing different decimation filters for processing PDM signals.

Features

• Reads raw data from a MEMS PDM microphone.
• Transfers data over serial communication using USB CDC.
• Data is sent in 1-bit format, encapsulated in packets of 8 bits.
• Utilizes Raspberry Pi Pico as the microcontroller.
• Provides a platform for testing various decimation filters for PDM signals.
• Uses TinyUSB library for USB CDC functionality.

Usage

1. Hardware Setup: Connect the MEMS PDM microphone to the Raspberry Pi Pico according to the provided specifications.

Raspberry Pi Pico / RP2040	PDM Microphone
3.3V	VCC
GND	GND
GPIO 17	DAT
GPIO 16	CLK

2. Software Setup: Clone this repository to your Raspberry Pi Pico development environment.
3. Compilation:
   • Ensure you have the Raspberry Pi's Pico SDK and required toolchains installed, such as TinyUSB. Refer to the official Raspberry Pi Pico documentation for detailed instructions.
   • Set the PICO_SDK environment variable to the path containing the Pico SDK.
   • Use the following commands to compile the code:

     mkdir build
     cd build
     cmake -G "NMake Makefiles" .. -DPICO_BOARD=pico -DFAMILY=rp2040 -DBOARD=raspberry_pi_pico
     nmake

4. Flash the UF2 file to Raspberry Pi Pico: Flash the compiled code onto the Raspberry Pi Pico microcontroller.
5. Connect to Serial Terminal: Use a serial terminal application to connect to the Raspberry Pi Pico over USB CDC. (Ensure appropriate drivers are installed if needed.)
6. View Data: Refer to the notebook in the example folder for instructions on how to use and visualize the data.

Note: A compiled UF2 version can be found under firmware.

Dependencies

• TinyUSB: A small and efficient USB stack for USB-enabled microcontrollers. Used for USB CDC communication.

License

This project is licensed under the MIT License.

Contact

For any inquiries or suggestions, feel free to reach out via GitHub.