I2C peripheral in use after soft reset

[jedgarpark]

CircuitPython version and board name

Adafruit CircuitPython 10.0.0-alpha.3 on 2025-05-02; Adafruit Fruit Jam with rp2350b

Code/REPL

Larsio Paint Music https://github.com/adafruit/Adafruit_Learning_System_Guides/pull/3013

Behavior

after soft reset (ctrl-D, saving file, etc.) Error initializing TLV320 DAC: I2C peripheral in use Hard reset will fix it.

Description

In the case of Larsio Paint Music, the program will still run, but there's no sound since the DAC hasn't been properly initialized.

Additional information

No response

[jedgarpark]

@tannewt I put the issue we discussed here

[todbot]

I am also seeing this on Adafruit CircuitPython 10.0.0-alpha.3 on 2025-05-02; Raspberry Pi Pico with rp2040 with the sample code below. On reset, the audio plays. Then if you Ctrl-C and Ctrl-D to restart, the error following error appears:

  File "code.py", line 14, in <module>
ValueError: I2C peripheral in use

This does not happen on Adafruit CircuitPython 10.0.0-alpha.2 on 2025-05-02; Raspberry Pi Pico with rp2040

Sample code:

import time, math, time
import ulab.numpy as np
import board, busio, audiobusio, audiocore, audiomixer
import adafruit_tlv320 

SAMPLE_RATE = 44100
CHANNEL_COUNT = 1
BUFFER_SIZE = 2048

i2c_sda_pin, i2c_scl_pin = board.GP16, board.GP17
i2s_bck_pin, i2s_lck_pin, i2s_dat_pin = board.GP20, board.GP21, board.GP22

i2c = busio.I2C(scl=i2c_scl_pin, sda=i2c_sda_pin)
audio = audiobusio.I2SOut(bit_clock=i2s_bck_pin, word_select=i2s_lck_pin, data=i2s_dat_pin)
dac = adafruit_tlv320.TLV320DAC3100(i2c)
dac.configure_clocks(sample_rate=SAMPLE_RATE, bit_depth=16)
dac.headphone_output = True
dac.headphone_volume = -35  # dB, does not seem to work? 

mixer = audiomixer.Mixer(sample_rate=SAMPLE_RATE, channel_count=CHANNEL_COUNT, buffer_size=BUFFER_SIZE)
audio.play(mixer)

# generate a sine wave
tone_volume = 0.5
frequency = 440
length = SAMPLE_RATE // frequency
sine_wave = np.array(np.sin(np.linspace(0, 2*np.pi, length, endpoint=False))
                     * tone_volume * 32767, dtype=np.int16)
sine_wave_sample = audiocore.RawSample(sine_wave, sample_rate=SAMPLE_RATE)

while True:
    mixer.voice[0].play(sine_wave_sample, loop=True)
    time.sleep(1)
    mixer.voice[0].stop()
    time.sleep(1)

[relic-se]

I'm having this error on Adafruit CircuitPython 10.0.0-alpha.3 on 2025-05-02; Pimoroni Pico Plus 2 with rp2350b with the following code:

import board, busio
i2c = busio.I2C(scl=board.GP19, sda=board.GP18)

Which results in:

Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
ValueError: I2C peripheral in use

The board-specific I2C is GP4/GP5 which is I2C0, whereas GP18/GP19 is I2C1. i2c = board.I2C() works without error.

[relic-se]

Brute force testing revealed that adafruit-circuitpython-...-20250426-main-PR10264-....uf2 is the first build to trigger this error. It must stem from the changes in #10264, and is related to garbage collection? Hopefully that'll get you something to start with, @tannewt.

[relic-se]

The following code also triggers an error on the #10264 build:

import board, pwmio
led = pwmio.PWMOut(board.LED)

Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
RuntimeError: Internal resource(s) in use

[tannewt]

Please try this branch: https://github.com/tannewt/circuitpython/tree/fix_finalisers

I think I broke finalisers in that change. I only have time to compile it now.

[todbot]

Yep, seems to have fixed it. My above test code on RP2040 works a second time after Ctrl-C, Ctrl-D, as well as a version of @relic-se's much simpler example of just creating a busio.I2C().

[jedgarpark]

yes, @tannewt this is fixed for me now too. Fruit Jam sucessfully re-initializing DAC on I2C after soft resets (both from file save and ctrl-D).

[relic-se]

Sorry for the late response, but the alpha.4 update fixes the bug for me too. Thanks @tannewt !