I2S

The I2S module is mainly used to drive I2S devices. The k210 has a total of 3 I2S devices and each device has a total of 4 channels. Before use, it is necessary to map and manage the pins.

1. Module functions

1.1. Constructor

Create a new I2S object

from Maix import I2S
i2s_dev = I2S (device_num)

parameters

device_num UART number, using the specified I2S, which can be completed by pressing the I2S.` tab

return value

Returns an I2S object

1.2. Channel configuration function

Used to configure I2S channels. Pin mapping is required before

i2s_dev.channel_config (channel, mode, resolution, cycles, align_mode)

parameters

• channel: I2S channel number

• mode: channel transmission mode. There are a total of receiving and sending modes.

• resolution: channel resolution, ie the number of received data bits

• cycles: number of single data clocks

• align_mode: channel alignment mode

return value

no

1.3. Set the sampling rate

Used to configure the I2S sampling rate

i2s_dev.set_sample_rate (sample_rate)

parameters

sample_rate:

return value

no

1.4. Receive audio

Receive audio data using I2S

audio = i2s_dev.record (points)

parameters

• points: audio points collected at one time

return value

audio: an audio audio object

1.5. Send audio

Send audio data using I2S

i2s_dev.play (audio)

parameters

• audio: the audio object to send

return value

no

2. Examples

2.1. Routine 1

from Maix import I2S
import time
fm.register (20, fm.fpioa.I2S0_IN_D0) #GO
fm.register (19, fm.fpioa.I2S0_WS)
fm.register (18, fm.fpioa.I2S0_SCLK)
fm.register (34, fm.fpioa.I2S2_OUT_D1)
fm.register (35, fm.fpioa.I2S2_SCLK)
fm.register (33, fm.fpioa.I2S2_WS)
sample_rate = 44 * 1000
rx = I2S (I2S.DEVICE_0)
rx.channel_config (rx.CHANNEL_0, rx.RECEIVER, align_mode = I2S.STANDARD_MODE)
rx.set_sample_rate (sample_rate)
tx = I2S (I2S.DEVICE_2)
tx.channel_config (tx.CHANNEL_1, tx.TRANSMITTER, align_mode = I2S.RIGHT_JUSTIFYING_MODE)
tx.set_sample_rate (sample_rate)
while True:
    audio = rx.record (256) #sampling points number must be smaller than 256
    tx.play (audio)

2.2. Routine 2

from Maix import I2S
from Maix import Audio
from Maix import FFT
import time
fm.register (20, fm.fpioa.I2S0_IN_D0)
fm.register (19, fm.fpioa.I2S0_WS)
fm.register (18, fm.fpioa.I2S0_SCLK)
fm.register (34, fm.fpioa.I2S2_OUT_D1)
fm.register (35, fm.fpioa.I2S2_SCLK)
fm.register (33, fm.fpioa.I2S2_WS)

rx = I2S (I2S.DEVICE_0)
rx.channel_config (rx.CHANNEL_0, rx.RECEIVER, align_mode = I2S.STANDARD_MODE)
rx.set_sample_rate (16000)
tx = I2S (I2S.DEVICE_2)
tx.channel_config (tx.CHANNEL_1, tx.TRANSMITTER, align_mode = I2S.RIGHT_JUSTIFYING_MODE)
tx.set_sample_rate (16000)

while True:
    audio = rx.record (256)
    audio_data = audio.to_bytes ()
    play_audio = Audio (audio_data)
    tx.play (play_audio)