Record audio from PDM Microphone and save to micro SD card using Circuitpython

Question

I am trying to record audio from PDM Microphone MP34DT05-A, and save it in .wav file format on the micro SD Card through SPI, using Circuitpython.

The microcontroller I used is Raspberry Pi Pico W.

Currently, I could not fine a way to save audio data to .wav file.

Here my code but I stuck at saving the audio:

import time
import array
import math
import board
import audiobusio
import digitalio
import busio
import adafruit_sdcard
import storage
import audiocore

# Main program
mic = audiobusio.PDMIn(board.GP3, board.GP2, sample_rate=16000, bit_depth=16)
samples = array.array('H', [0] * 160)
filename = "/sd/recording1.wav"
record_time = 15  # seconds
sample_rate = 16000

# Initialize SPI bus and SD card.
# Initialize micro SD Card SPI pins
SCK_PIN = board.GP18
MOSI_PIN = board.GP19
MISO_PIN = board.GP16
CS_PIN = board.GP17

spi = busio.SPI(SCK_PIN, MOSI=MOSI_PIN, MISO=MISO_PIN)
cs = digitalio.DigitalInOut(CS_PIN)

sdcard = adafruit_sdcard.SDCard(spi, cs)

# Mount SD card filesystem.
vfs = storage.VfsFat(sdcard)
mount_result = None
try:
    storage.mount(vfs, "/sd")
except Exception as e:
    print("Error mounting filesystem:", e)
    time.sleep(1)

# Create a WaveWrite object
with audiocore.WaveFile(open(filename, "wb")) as f:
    while record_time > 0:
        mic.record(samples, len(samples))
        print(samples)
        f.write(bytes(samples))
        record_time -= 1

print("Recording complete!")

Any suggestion or ideas would be helpful. Thank you.