Merge pull request #298 from 092vk/axon: audio: Microphone

axon: audio: analog microphone: Added config and usage doc

Author: avi951

source/_static/images/rk3588-axon/axon-mic.webp

@@ -1,10 +1,276 @@
-
-
 #################
 Analog MIC
 #################
 
-.. note::
+.. image:: /_static/images/rk3588-axon/axon-mic.webp
+   :width: 70%
+
+The Analog MIC input on the Axon board provides a flexible interface for acoustic sensing using a broad class of analog microphone technologies. Axon provides support for mics of different types and companies at the same time preserving dynamic range while minimizing noise.
+
+Wiring and connectors
+----------------------
+
+* For Single ended interface mic:
+
+  * Mic output → ANALOG_MIC pin (+)
+  * Mic ground → GND (GPIO GND) on axon header
+
+* For Differential interface mic:
+
+  * Mic output → ANALOG_MIC pin (+)
+  * Mic ground → ANALOG_MIC pin (-)
+
+How to Setup
+------------
+
+Follow these steps to connect and use an analog microphone with the Axon board.
+
+1. Connect the microphone
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Connect your microphone to the Axon board:
+
+* If you are using single interface mic, just connect MIC_OUT to ANALOG_MIC PIN (+) and Microphone ground → Axon GND (Connect to GPIO GND)
+* Otherwise if you are using differential mic, connect MIC_OUT to ANALOG_MIC PIN (+) and MIC_GND to ANALOG_MIC PIN (-)
+
+Refer to the Axon pinout documentation for exact pin locations `Axon Pinouts <https://docs.vicharak.in/vicharak_sbcs/axon/peripherals/gpio/#axon-gpios-header>`_
+
+2. Detect the microphone
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+Boot the Axon board and open a terminal.
+
+Run:
+
+.. code-block:: bash
+
+   arecord -l
+
+This will list available recording devices.
+
+Example output:
+
+.. code-block:: text
+
+      vicharak@vicharak:~$ aplay -l
+    **** List of PLAYBACK Hardware Devices ****
+    card 0: rockchipes8388 [rockchip-es8388], device 0: dailink-multicodecs ES8323 HiFi-0 [dailink-multicodecs ES8323 HiFi-0]
+      Subdevices: 1/1
+      Subdevice #0: subdevice #0
+    card 1: rockchipdp0 [rockchip-dp0], device 0: rockchip-dp0 spdif-hifi-0 [rockchip-dp0 spdif-hifi-0]
+      Subdevices: 1/1
+      Subdevice #0: subdevice #0
+    card 2: rockchipdp1 [rockchip-dp1], device 0: rockchip-dp1 spdif-hifi-0 [rockchip-dp1 spdif-hifi-0]
+      Subdevices: 1/1
+      Subdevice #0: subdevice #0
+    card 3: rockchiphdmi0 [rockchip-hdmi0], device 0: rockchip-hdmi0 i2s-hifi-0 [rockchip-hdmi0 i2s-hifi-0]
+      Subdevices: 1/1
+      Subdevice #0: subdevice #0
+    card 4: rockchiphdmi1 [rockchip-hdmi1], device 0: rockchip-hdmi1 i2s-hifi-0 [rockchip-hdmi1 i2s-hifi-0]
+      Subdevices: 1/1
+      Subdevice #0: subdevice #0
+
+* Look for rockchipes8388, it contains **ES8388** which is an analog audio codec chip, which handles: audio. 
+* Note down the device and card number to be used in below commands
+
+* In this example: ``card 0, device 0 → plughw:0,0`` is used 
+
+3. Record Audio from Microphone
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Prerequisites
+"""""""""""""
+
+Ensure:
+
+* Microphone is properly connected to the SBC
+* ALSA utilities are installed
+
+Install if needed:
+
+.. code-block:: bash
+
+   sudo apt install alsa-utils
+
+Step 1: Record Audio
+""""""""""""""""""""
+
+Record audio using:
+
+.. code-block:: bash
+
+   arecord -D plughw:0,0 -f S16_LE -r 16000 -c 1 test.wav
+
+Parameter Explanation
+,,,,,,,,,,,,,,,,,,,,,
+
+.. list-table::
+   :header-rows: 1
+   :widths: 20 60
+
+   * - Parameter
+     - Meaning
+   * - ``-D plughw:0,0``
+     - Select microphone device
+   * - ``-f S16_LE``
+     - 16-bit signed little-endian format
+   * - ``-r 16000``
+     - Sampling rate (16 kHz)
+   * - ``-c 1``
+     - Mono recording
+   * - ``test.wav``
+     - Output file
+
+Step 2: Stop Recording
+""""""""""""""""""""""
+
+Press:
+
+.. code-block:: text
+
+   Ctrl + C
+
+The audio will be saved as ``test.wav``
+
+Step 3: Playback Recorded Audio
+"""""""""""""""""""""""""""""""
+
+Verify recording:
+
+.. code-block:: bash
+
+   aplay test.wav
+
+Recommended Settings for Speech Applications
+"""""""""""""""""""""""""""""""""""""""""""""
+
+Use:
+
+.. code-block:: bash
+
+   arecord -D plughw:0,0 -f S16_LE -r 16000 -c 1 speech.wav
+
+This configuration is ideal for:
+
+* Speech recognition
+* Voice assistants
+* Embedded AI applications
+
+
+Notes
+,,,,,
+
+* Use ``plughw`` instead of ``hw`` to allow automatic format conversion
+* 16 kHz mono is sufficient for most voice applications
+* Higher sample rates (e.g., 44100 Hz) may be used for higher quality audio
+
+Example:
+
+.. code-block:: bash
+
+   arecord -D plughw:0,0 -f S16_LE -r 44100 -c 2 audio.wav
+
+
+Troubleshooting
+---------------
+
+Quick Diagnostic Commands
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+List supported hardware parameters:
+
+.. code-block:: bash
+
+   arecord -D hw:0,0 --dump-hw-params
+
+Check microphone levels:
+
+.. code-block:: bash
+
+   alsamixer
+
+Press ``F4`` → Capture devices
+
+Increase capture volume if needed.
+
+---
+
+No audio detected
+^^^^^^^^^^^^^^^^^
+
+Check the following:
+
+* Microphone is connected correctly
+* Ground connection is secure
+* Microphone output is connected to MIC input
+* Device is visible using:
+
+  .. code-block:: bash
+
+     arecord -l
+
+* Capture volume is not muted:
+
+  .. code-block:: bash
+
+     alsamixer
+
+  Press F4 and increase Capture volume.
+
+---
+
+Low audio volume
+^^^^^^^^^^^^^^^^
+
+Possible solutions:
+
+* Increase microphone gain using:
+
+  .. code-block:: bash
+
+     alsamixer
+
+* Use a microphone module with built-in amplifier
+* Move closer to the microphone
+
+---
+
+Excessive noise or interference
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Check the following:
+
+* Ensure proper grounding
+* Keep microphone wires short
+* Avoid routing microphone wires near power or digital signal lines
+* Use shielded cables if necessary
+
+---
+
+Hum or buzzing sound
+^^^^^^^^^^^^^^^^^^^^
+
+Possible causes:
+
+* Ground loop issues
+* Poor shielding
+* Electrical interference from nearby components
+
+Solutions:
+
+* Ensure common ground between microphone and Axon
+* Use shielded microphone cable
+* Keep microphone away from power sources and high-frequency components
+
+---
+
+Verification Checklist
+----------------------
+
+Ensure the following:
 
-   **Documentation coming soon!** 
-   This section will be updated shortly with detailed instructions and information. Stay tuned for more!
+* Microphone is securely connected
+* Microphone appears in ``arecord -l``
+* Audio recording works using ``arecord``
+* Audio playback works using ``aplay``
+* Capture volume is properly set using ``alsamixer``