Writing from SD Card to Flash Memery

[Nicolebendo]

Hi, i'm using a raspberry Pico running on CircuitPython,
I'm trying to play multiple sounds at the same time using this piece of code:

Code: Select all

import time
import board
import audiocore
import audiomixer
from audiopwmio import PWMAudioOut as AudioOut

num_voices = 2

audio = AudioOut(board.GP18, right_channel=board.GP19)
mixer = audiomixer.Mixer(voice_count=num_voices, sample_rate=22050, channel_count=1,
                         bits_per_sample=16, samples_signed=True)
audio.play(mixer)

mixer.voice[0].level = 1.0
mixer.voice[1].level = 1.0

wave0 = audiocore.WaveFile(open("/drumsacuff_22k_s16.wav","rb"))
mixer.voice[0].play( wave0, loop=True )

wave1 = audiocore.WaveFile(open("/snowpeaks_22k_s16.wav","rb"))
mixer.voice[1].play( wave1, loop=True )

This works perfectly when the files are stored directly on the pico. But when I try with files stored on a sd card it doesn't work anymore (note that it works fine with only 1 file from the sd card, or 1 file from the sd card and multiple files from the raspberry pico main direcrtory)

Couldn't I just temporary store a .wav file from the sd card into a variable or someting like this, so that it is temporary stored on the raspberry pico ?
Or can I copy the some .wav files from sd card to the raspberry main directory in order to play them and then delete them when I'm finished with them ?

Thank you for your hekp ! :)

[mikeysklar]

Is there any reason not keep all your files on the Pico USB drive and just skip the SD card? If space is an issue maybe using MP3? I suspect you have a constraint that requires the SD card, but just checking.

You should be able to write to CircuitPython flash from your code by modifying the boot.py. Take a look at the example boot.py and code.py here for making a datalogger to flash space.

https://github.com/edgecollective/circu ... m0_express

boot.py:

Code: Select all

import digitalio
import board
import storage

switch=digitalio.DigitalInOut(board.D6)
switch.switch_to_input()

storage.remount("/",not switch.value) # switch.value==False means datalogging mode:  allow circuitpython code to write to flash, while making USB read-only.  So: pull D6 high for datalogging, leave D6 at ground for USB write access (reprogramming).

code.py

Code: Select all

import digitalio
import board
import time

switch=digitalio.DigitalInOut(board.D6)
switch.switch_to_input()

led = digitalio.DigitalInOut(board.D13)
led.switch_to_output()

if switch.value==True: # if pin D6 is pulled high, then datalog mode -- no USB write allowed
    for i in range(10): # keep number of writes low for testing
        f=open('data.txt','a')
        f.write('{:03d}\n'.format(i))
        f.close()
        led.value = not led.value # blink to indicate successful write
        time.sleep(1)
        
else:
    while True:
        led.value = not led.value #faster blink to indicate in USB read-write mode
        time.sleep(.2)

Once you get a writable flash space then you need to figure out the equivalent of copy. I'll think about how to do that.