AM3358: I2S microphone array recording issue

I created sd card with latest ti sdk for am335x and following by this guide http://www.ti.com/lit/an/sprac97/sprac97.pdf I added the pcm1864 array microphone and still the issue  described earlier is present.

The true record is only available with fs = 96kHz, with any other fs the speed of recording is faster or slower than realtime

Marcin,

In this forum (Processors forum), we support AM335x device, from the devices listed in SPRAC97 document.

In SPRAC97 document, we have AM335x McASP1 module receive I2S audio data from C5517 DSP. AM335x McASP1 receives I2S audio data from 3 pins: bit clock (mcasp1_aclkx), sample rate (mcasp1_fsx) and data in (mcasp1_axr0).

The sample rate is 16KHz, which is one of the supported sample rates, for full list refer to below wiki page:

Regarding AM335x McAPS1 module, what issue exactly you have with it? Do you try to receive audio data from more than one pin? Do you need to receive data not only from mcasp1_axr0 pin, but from more axr pins?

Regards,
Pavel

I'm trying to record simple audio with arecord. I have pcm1864 directly connected to beaglebone:

24 -> P9 19

23 -> P9 20

18 -> P9 41

16 -> P9 27

17 -> P9 42 

Acording to i2s specs and 1864 data sheet... Is it possible to connnect pcm1864 as 4 channel audio input by i2s to beaglebone or I need to configure this in tdm format?

Marcin Rosiek said:

I'm trying to record simple audio with arecord. I have pcm1864 directly connected to beaglebone:

24 -> P9 19

23 -> P9 20

18 -> P9 41

16 -> P9 27

17 -> P9 42 

BeagleBone Black board has AM335x device of type ZCZ, thus you are using below pins:

P9_19 is D17 UART1_RTSn

P9_20 is D18 UART1_CTSn

P9_41 is D14 XDMA_EVENT_INTR1

P9_27 is C13 MCASP0_FSR

P9_42 is C18 ECAP0_IN_PWM0_OUT

From all these pins, only C13 can be selected to mcasp1_fsx. All other pins do not have McASP1 pinmux options. Please revise you HW pinout connection.

Regards,
Pavel

Marcin Rosiek said:

Acording to i2s specs and 1864 data sheet... Is it possible to connnect pcm1864 as 4 channel audio input by i2s to beaglebone or I need to configure this in tdm format?

For AM335x McASP input options and formats, please refer to AM335x TRM, ch22 McASP. Below doc might be also useful:

Regards,
Pavel

I created dts file for using tdm and driver pcm186x from ti sdk. When recording with arecord the clock of BCK is changing, the output data is generated (view by osciloscope) but system returns: arecord: pcm_read:2143: read error: Input/output error

My dts:

&am33xx_pinmux {
    myi2c1_pins_default: myi2c1_pins_default {
        pinctrl-single,pins = <
            AM33XX_IOPAD(0x95c, PIN_INPUT_PULLUP | MUX_MODE2) /* (A16) spi0_cs0.I2C1_SCL P9_17   */
            AM33XX_IOPAD(0x958, PIN_INPUT_PULLUP | MUX_MODE2) /* (B16) spi0_d1.I2C1_SDA P8_18  */
        >;
    };

    /* Optional sleep pin settings. Must manually enter values in the below skeleton. */
    myi2c1_pins_sleep: myi2c1_pins_sleep {
        pinctrl-single,pins = <
            AM33XX_IOPAD(0x95c,  PIN_INPUT_PULLUP | MUX_MODE2) /* (A16) spi0_cs0.I2C1_SCL */
            AM33XX_IOPAD(0x958,  PIN_INPUT_PULLUP | MUX_MODE2) /* (B16) spi0_d1.I2C1_SDA */
        >;
    };

    mymcasp0_pins_default: mymcasp0_pins_default {
        pinctrl-single,pins = <
            0xd0 ( PIN_INPUT_PULLUP | MUX_MODE3 ) /* (V2) lcd_data12.mcasp0_aclkr */
            0xd4 ( PIN_INPUT_PULLUP | MUX_MODE3 ) /* (V3) lcd_data13.mcasp0_fsr */
            0xc8 ( PIN_OUTPUT | MUX_MODE3 ) /* (U3) lcd_data10.mcasp0_axr0 */
            0xd8 ( PIN_INPUT_PULLUP | MUX_MODE3 ) /* (V4) lcd_data14.mcasp0_axr1 */
            0xcc ( PIN_INPUT_PULLUP | MUX_MODE4 ) /* (U4) lcd_data11.mcasp0_axr2 */
        >;
    };

};


&mcasp0 {
        #sound-dai-cells = <0>;
        pinctrl-names = "default";
        pinctrl-0 = <&mymcasp0_pins_default>;

        status = "okay";

        op-mode = <0>;          /* MCASP_IIS_MODE */
        tdm-slots = <2>;
        serial-dir = <    /* 0: INACTIVE, 1: TX, 2: RX */
            0 2 2 0
            >;
        tx-num-evt = <32>;
        rx-num-evt = <32>;
};

&i2c1 {
    pinctrl-names = "default", "sleep";
    pinctrl-0 = <&myi2c1_pins_default>;
    pinctrl-1 = <&myi2c1_pins_sleep>;

    status = "okay";
    clock-frequency = <100000>;

    pcm1865: pcm1865@4a {
        compatible = "ti,pcm1865";
        #sound-dai-cells = <0>;
        reg = <0x4a>;
        status = "okay";
        /* Regulators */
        AVDD-supply = <&vmmcsd_fixed>;
        IOVDD-supply = <&vmmcsd_fixed>;
        DVDD-supply = <&vmmcsd_fixed>;
    };
};


/ {
    pcm5102a: pcm5102a {
        #sound-dai-cells = <0>;
        compatible = "ti,pcm5102a";
        status = "okay";
    };
    
    sound {
    compatible = "simple-audio-card";
    simple-audio-card,name = "ADC Sound";

    simple-audio-card,widgets =
            "Line", "Line In Jack 1",
            "Line", "Line In Jack 2",
            "Line", "Line In Jack 3",
            "Line", "Line In Jack 4";
    simple-audio-card,routing =
            "Line In Jack 1", "VINL1",
            "Line In Jack 1", "VINR1",
            "Line In Jack 2", "VINL2",
            "Line In Jack 2", "VINR2",
            "Line In Jack 3", "VINL3",
            "Line In Jack 3", "VINR3",
            "Line In Jack 4", "VINL4",
            "Line In Jack 4", "VINR4";

    simple-audio-card,format = "i2s";

    simple-audio-card,bitclock-master = <&sound0_master>;
    simple-audio-card,frame-master = <&sound0_master>;

    simple-audio-card,cpu {
        sound-dai = <&mcasp0>;
        system-clock-frequency = <24576000>;
        system-clock-direction = "in";
    };

    sound0_master: simple-audio-card,codec {
        sound-dai = <&pcm1865>;
        system-clock-frequency = <24576000>;
    };
};


};

Marcin Rosiek said:

When recording with arecord the clock of BCK is changing, the output data is generated (view by osciloscope) but system returns: arecord: pcm_read:2143: read error: Input/output error

The input and output error typically happens when the ALSA PCM device is not consuming any data. Check again with scope if you have valid data transfer from PCM1865 codec to AM335x McASP module through the axr pins. Check also below user guide, section 6.7 Input and Output Error During Audio Record

Regards,
Pavel