此外、每当我尝试将时钟(McASP1_ACLKR (位时钟)- P9_42)与示波器连接时、我都看不到任何脉冲。 似乎该引脚上没有适当的时钟信号。 我该如何进行调试和修复？
有什么想法吗？
Parag
请注意，本文内容源自机器翻译，可能存在语法或其它翻译错误，仅供参考。如需获取准确内容，请参阅链接中的英语原文或自行翻译。
器件型号：AM3359 主题中讨论的其他器件：PCM5102A、 PCM1864
工具/软件：Linux
我尝试将 I2S 麦克风(https://www.adafruit.com/product/3421)与 BeagleBone Black 连接。 我遵循了文章(http://www.ti.com/lit/an/sprac97/sprac97.pdf)、并按照文章中的建议更新了器件树和 Linux 内核。
器件树的 I2S 组件(用于麦克风)作为 dtsi 包含在主器件树源代码中。 dtsi 的内容如下所示
&am33xx_pinmux {
mcasp1_pins: mcasp1_pins {
pinctrl-single,pins = <
/* sink must enable receivers */
0x1a0 0x23
/* P9_42 mcasp1_aclkx - bit clock */
0x1a4 0x23
/* P9_27 mcasp1_fsx - frame sync */
0x1a8 0x23
/* P9_41 mcasp1_axr0 - i2s input */
>;
};
};
&mcasp1 {
#sound-dai-cells = <0>;
pinctrl-names = "default";
pinctrl-0 = <&mcasp1_pins>;
status = "okay";
op-mode = <0>;
tdm-slots = <2>;
num-serializer = <4>;
serial-dir = < /* 1 TX 2 RX 0 unused */
2 0 0 0
>;
rx-num-evt = <1>;
tx-num-evt = <1>;
};
/ {
pcm5102a: pcm5102a {
#sound-dai-cells = <0>;
compatible = "ti,pcm5102a";
status = "okay";
};
sound1: sound@1 {
compatible = "simple-audio-card";
simple-audio-card,name = "PCM5102a";
simple-audio-card,format = "i2s";
simple-audio-card,bitclock-master = <&sound1_master>;
simple-audio-card,frame-master = <&sound1_master>;
simple-audio-card,bitclock-inversion;
simple-audio-card,cpu {
sound-dai = <&mcasp1>;
};
sound1_master: simple-audio-card,codec {
#sound-dai-cells = <0>;
sound-dai = <&pcm5102a>;
clocks = <&mcasp1_fck>;
clock-names = "mclk";
};
};
};
I have also compiled the kernel with a new driver pcm5102 as suggested in the document. Finally, I see the driver listed in the output of the arecord command.
root@arm:/sys/class/gpio# arecord -l **** List of CAPTURE Hardware Devices **** card 0: PCM5102a [PCM5102a], device 0: davinci-mcasp.0-pcm5102a-hifi pcm5102a-hifi-0 [] Subdevices: 1/1 Subdevice #0: subdevice #0
但是、每当我尝试录制音频时、我都无法获取任何音频数据。 音频文件是格式、但无论我尝试录制音频的时间长短、文件大小始终为44字节。 显然、文件中没有数据。
使用 arecord 命令进行记录时出现错误、如下所示
arecord -d 10 -Dhw:0,0 -f dat audio.wav Recording WAVE 'audio.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo arecord: pcm_read:2032: read error: Input/output error
