Merge branch 'main' into 'main'

Fixes, contnet and release script

See merge request docs/docs.beagleboard.io!27

.gitlab-ci.yml

+# You can override the included template(s) by including variable overrides
+# SAST customization: https://docs.gitlab.com/ee/user/application_security/sast/#customizing-the-sast-settings
+# Secret Detection customization: https://docs.gitlab.com/ee/user/application_security/secret_detection/#customizing-settings
+# Dependency Scanning customization: https://docs.gitlab.com/ee/user/application_security/dependency_scanning/#customizing-the-dependency-scanning-settings
+# Note that environment variables can be set in several places
+# See https://docs.gitlab.com/ee/ci/variables/#cicd-variable-precedence
 image: beagle/sphinx-build-env:latest
 
-stages:
-  - deploy
+variables:
+  GIT_SUBMODULE_STRATEGY: recursive
 
 cache:
   key: bbdocs
   paths:
-    - public
+  - public
 
 pages:
   stage: deploy
   script:
-    - ./gitlab-build.sh
+  - "./gitlab-build.sh"
   artifacts:
     paths:
-      - public
+    - public

.gitmodules

+[submodule "books/beaglebone-cookbook/code"]
+	path = books/beaglebone-cookbook/code
+	url = https://git.beagleboard.org/beagleboard/beaglebone-cookbook-code.git

Dockerfile

@@ -8,3 +8,4 @@ RUN apk add librsvg
 RUN pip install sphinx_rtd_theme
 RUN apk add texlive-full
 RUN apk add make
+RUN apk add rsync

_ext/callouts.py

+from docutils import nodes
+
+from sphinx.util.docutils import SphinxDirective
+from sphinx.transforms import SphinxTransform
+from docutils.nodes import Node
+
+# BASE_NUM = 2775  # black circles, white numbers
+BASE_NUM = 2459  # white circle, black numbers
+
+
+class CalloutIncludePostTransform(SphinxTransform):
+    """Code block post-processor for `literalinclude` blocks used in callouts."""
+
+    default_priority = 400
+
+    def apply(self, **kwargs) -> None:
+        visitor = LiteralIncludeVisitor(self.document)
+        self.document.walkabout(visitor)
+
+
+class LiteralIncludeVisitor(nodes.NodeVisitor):
+    """Change a literal block upon visiting it."""
+
+    def __init__(self, document: nodes.document) -> None:
+        super().__init__(document)
+
+    def unknown_visit(self, node: Node) -> None:
+        pass
+
+    def unknown_departure(self, node: Node) -> None:
+        pass
+
+    def visit_document(self, node: Node) -> None:
+        pass
+
+    def depart_document(self, node: Node) -> None:
+        pass
+
+    def visit_start_of_file(self, node: Node) -> None:
+        pass
+
+    def depart_start_of_file(self, node: Node) -> None:
+        pass
+
+    def visit_literal_block(self, node: nodes.literal_block) -> None:
+        if "<1>" in node.rawsource:
+            source = str(node.rawsource)
+            for i in range(1, 20):
+                source = source.replace(
+                    f"<{i}>", "``" + chr(int(f"0x{BASE_NUM + i}", base=16)) + "``"
+                )
+            node.rawsource = source
+            node[:] = [nodes.Text(source)]
+
+
+class callout(nodes.General, nodes.Element):
+    """Sphinx callout node."""
+
+    pass
+
+
+def visit_callout_node(self, node):
+    """We pass on node visit to prevent the
+    callout being treated as admonition."""
+    pass
+
+
+def depart_callout_node(self, node):
+    """Departing a callout node is a no-op, too."""
+    pass
+
+
+class annotations(nodes.Element):
+    """Sphinx annotations node."""
+
+    pass
+
+
+def _replace_numbers(content: str):
+    """
+    Replaces strings of the form <x> with circled unicode numbers (e.g. ①) as text.
+
+    Args:
+        content: Python str from a callout or annotations directive.
+
+    Returns: The formatted content string.
+    """
+    for i in range(1, 20):
+        content.replace(f"<{i}>", chr(int(f"0x{BASE_NUM + i}", base=16)))
+    return content
+
+
+def _parse_recursively(self, node):
+    """Utility to recursively parse a node from the Sphinx AST."""
+    self.state.nested_parse(self.content, self.content_offset, node)
+
+
+class CalloutDirective(SphinxDirective):
+    """Code callout directive with annotations for Sphinx.
+
+    Use this `callout` directive by wrapping either `code-block` or `literalinclude`
+    directives. Each line that's supposed to be equipped with an annotation should
+    have an inline comment of the form "# <x>" where x is an integer.
+
+    Afterwards use the `annotations` directive to add annotations to the previously
+    defined code labels ("<x>") by using the syntax "<x> my annotation" to produce an
+    annotation "my annotation" for x.
+    Note that annotation lines have to be separated by a new line, i.e.
+
+    .. annotations::
+
+        <1> First comment followed by a newline,
+
+        <2> second comment after the newline.
+
+
+    Usage example:
+    -------------
+
+    .. callout::
+
+        .. code-block:: python
+
+            from ray import tune
+            from ray.tune.search.hyperopt import HyperOptSearch
+            import keras
+
+            def objective(config):  # <1>
+                ...
+
+            search_space = {"activation": tune.choice(["relu", "tanh"])}  # <2>
+            algo = HyperOptSearch()
+
+            tuner = tune.Tuner(  # <3>
+                ...
+            )
+            results = tuner.fit()
+
+        .. annotations::
+
+            <1> Wrap a Keras model in an objective function.
+
+            <2> Define a search space and initialize the search algorithm.
+
+            <3> Start a Tune run that maximizes accuracy.
+    """
+
+    has_content = True
+
+    def run(self):
+        self.assert_has_content()
+
+        content = self.content
+        content = _replace_numbers(content)
+
+        callout_node = callout("\n".join(content))
+        _parse_recursively(self, callout_node)
+
+        return [callout_node]
+
+
+class AnnotationsDirective(SphinxDirective):
+    """Annotations directive, which is only used nested within a Callout directive."""
+
+    has_content = True
+
+    def run(self):
+        content = self.content
+        content = _replace_numbers(content)
+
+        joined_content = "\n".join(content)
+        annotations_node = callout(joined_content)
+        _parse_recursively(self, annotations_node)
+
+        return [annotations_node]
+
+
+def setup(app):
+    # Add new node types
+    app.add_node(
+        callout,
+        html=(visit_callout_node, depart_callout_node),
+        latex=(visit_callout_node, depart_callout_node),
+        text=(visit_callout_node, depart_callout_node),
+    )
+    app.add_node(annotations)
+
+    # Add new directives
+    app.add_directive("callout", CalloutDirective)
+    app.add_directive("annotations", AnnotationsDirective)
+
+    # Add post-processor
+    app.add_post_transform(CalloutIncludePostTransform)
+
+    return {
+        "version": "0.1",
+        "parallel_read_safe": True,
+        "parallel_write_safe": True,
+    }

boards/beaglebone/ai-64/index.rst

@@ -16,4 +16,5 @@ BeagleBone® AI-64 brings a complete system for developing artificial intelligen
    /boards/beaglebone/ai-64/ch09.rst
    /boards/beaglebone/ai-64/ch10.rst
    /boards/beaglebone/ai-64/ch11.rst
+   /boards/beaglebone/ai-64/update.rst
    /boards/beaglebone/ai-64/edge_ai_apps/index.rst

boards/beaglebone/ai-64/update.rst

+.. _bbai64-update:
+
+Update software on BeagleBone AI-64
+###################################
+
+Production boards currently ship with the factory-installed 2022-01-14-8GB image. To upgrade from the software image on your BeagleBone AI-64 to the latest, you don't need to completely reflash the board. If you do want to reflash it, visit the flashing instructions on the getting started page.
+Factory Image update (without reflashing)…
+
+.. code-block:: bash
+   :linenos:
+
+   sudo apt update
+   sudo apt install --only-upgrade bb-j721e-evm-firmware generic-sys-mods
+   sudo apt upgrade
+
+Update U-Boot:
+==============
+
+to ensure only tiboot3.bin is in boot0, the pre-production image we tried to do more in boot0, but failed…
+
+.. code-block:: bash
+   :linenos:
+
+   sudo /opt/u-boot/bb-u-boot-beagleboneai64/install-emmc.sh
+   sudo /opt/u-boot/bb-u-boot-beagleboneai64/install-microsd.sh
+   sudo reboot
+
+Update Kernel and SGX modules:
+==============================
+
+.. code-block:: bash
+   :linenos:
+
+   sudo apt install bbb.io-kernel-5.10-ti-k3-j721e    
+
+Update xfce:
+============
+
+.. code-block:: bash
+   :linenos:
+
+   sudo apt install bbb.io-xfce4-desktop
+
+Update ti-edge-ai 8.2 examples
+==============================
+
+.. code-block:: bash
+   :linenos:
+
+   sudo apt install ti-edgeai-8.2-base ti-vision-apps-8.2 ti-vision-apps-eaik-firmware-8.2
+
+Cleanup:
+========
+
+.. code-block:: bash
+   :linenos:
+
+   sudo apt autoremove --purge
+
+

boards/beaglebone/index.rst

@@ -10,7 +10,8 @@ The most popular design is :ref:`beagleboneblack-home`, a staple reference for a
 embedded Linux single board computer.
 
 :ref:`bbai64-home` is our most powerful design with tremendous machine learning inference
-performance and 
+performance, 64-bit processing and a mixture of microcontrollers for various types of
+highly-reliable and low-latency control.
 
 For simplicity of developing small, mobile robotics, check out :ref:`beaglebone-blue-home`, a highly
 integrated board with motor drivers, battery support, altimeter, gyroscope, accelerometer,
@@ -24,6 +25,6 @@ of your screen.
 * `BeagleBone (original) <https://git.beagleboard.org/beagleboard/beaglebone/-/blob/master/BeagleBone_SRM_A6_0_1.pdf>`__
 * :ref:`beagleboneblack-home`
 * :ref:`beaglebone-blue-home`
-* :ref:`bbai64-home`
 * :ref:`beaglebone-ai-home`
+* :ref:`bbai64-home`
 

boards/beagleconnect/freedom/index.rst

+.. _beagleconnect_freedom_home:
+
 BeagleConnect Freedom
 ######################
 
+.. important::
+
+   Currently under development
+
 .. image:: media/image1.jpg
    :width: 600
    :align: center
@@ -29,12 +35,12 @@ devices within the first year after the initial release.
 BeagleConnect™ Freedom
 **********************
 
-BeagleConnect™ Freedom is based on the `TI CC1352 <https://www.ti.com/product/CC1352P7>`_ 
+BeagleConnect™ Freedom is based on a `TI Arm Cortex-M4 wireless-enabled microcontroller <https://www.ti.com/product/CC1352P7>`_ 
 and is the first available BeagleConnect™ solution. It implements:
 
 * BeagleConnect™ gateway device function for Sub-GHz 802.15.4 long-range 
   wireless
-* BeagleConnect™ node device function for Bluetooth Low-Energe (BLE) and 
+* BeagleConnect™ node device function for Bluetooth Low-Energy (BLE) and 
   Sub-GHz 802.15.4 long range wireless
 * USB-based serial console and firmware updates
 * 2x `mikroBUS sockets <https://www.mikroe.com/mikrobus>`_ with BeagleConnect™ 
@@ -125,7 +131,7 @@ Long-range, low-power wireless
 ==============================
 
 BeagleConnect™ Freedom wireless hardware is built around a 
-`TI CC1352 <http://www.ti.com/product/CC1352P7>`_ multiprotocol and multi-band 
+`TI CC1352P7 <http://www.ti.com/product/CC1352P7>`_ multiprotocol and multi-band 
 Sub-1 GHz and 2.4-GHz wireless microcontroller (MCU). CC1352P7 includes a 48-MHz
 Arm® Cortex®-M4F processor, 704KB Flash, 256KB ROM, 8KB Cache SRAM, 144KB of 
 ultra-low leakage SRAM, and `Over-the-Air <https://en.wikipedia.org/wiki/Over-the-air_programming>`_ 

boards/beagleconnect/freedom/zephyr.rst

@@ -73,6 +73,57 @@ BeagleBone® Green Gateway host.
 
 #TODO: describe how to know it is working
 
+Other systems
+-------------
+
+.. important::
+
+    If you are using the image above, none of the instructions in this section are required.
+
+#. Update the system.
+    .. code-block:: bash
+        
+        sudo apt update
+
+#. Install all BeagleConnect™ management software.
+    .. code-block:: bash
+
+        sudo apt install -y \
+        beagleconnect beagleconnect-msp430 \
+        git vim \
+        build-essential \
+        cmake ninja-build gperf \
+        ccache dfu-util device-tree-compiler \
+        make gcc libsdl2-dev \
+        libxml2-dev libxslt-dev libssl-dev libjpeg62-turbo-dev \
+        gcc-arm-none-eabi libnewlib-arm-none-eabi \
+        libtool-bin pkg-config autoconf automake libusb-1.0-0-dev \
+        python3-dev python3-pip python3-setuptools python3-tk python3-wheel
+
+    .. code-block:: bash
+
+        echo "export PATH=$PATH:$HOME/.local/bin" >> $HOME/.bashrc
+
+    .. code-block:: bash
+
+        source $HOME/.bashrc
+
+#. Reboot
+    .. code-block:: bash
+
+        sudo reboot
+
+#. Install BeagleConnect™ flashing software
+    .. code-block:: bash
+
+        pip3 install -U west
+
+#. Reboot
+    .. code-block:: bash
+
+        sudo reboot
+
+
 Log into BeagleBone Green Gateway
 =================================
 
@@ -86,7 +137,6 @@ computer can be used to connect to your BeagleBone Green Gateway.
     * To connect you can simply type :code:`$ ssh debian@192.168.7.2` and when 
       asked for password just type :code:`temppwd`
     * Congratulations, You are now connected to the device!
-
 #. Connect to the `WiFi <https://forum.beagleboard.org/t/debian-11-x-bullseye-monthly-snapshots/31280>`_
     * Execute :code:`sudo nano /etc/wpa_supplicant/wpa_supplicant-wlan0.conf` 
       and provide the password :code:`temppwd` to edit the configuration file 
@@ -94,7 +144,8 @@ computer can be used to connect to your BeagleBone Green Gateway.
     * Now edit the file (shown below) under the :code:`network={...}`
       section you can set you :code:`ssid` (WiFi name) and :code:`psk` (Wifi 
       Password).
-    .. code-block::
+
+      .. code-block::
 
         ctrl_interface=DIR=/run/wpa_supplicant GROUP=netdev
         update_config=1
@@ -103,10 +154,12 @@ computer can be used to connect to your BeagleBone Green Gateway.
                 ssid="WiFi Name"
                 psk="WiFi Password"
         }
+
     * Now save the file with :code:`CTRL+O` and exit with :code:`CTRL+X`.
     * Check if the connection is established by executing :code:`$ ping 8.8.8.8`
       you should see something like shown below.
-    .. code-block:: bash
+
+      .. code-block:: bash
 
         debian@BeagleBone:~$ ping 8.8.8.8
         PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
@@ -115,62 +168,24 @@ computer can be used to connect to your BeagleBone Green Gateway.
         64 bytes from 8.8.8.8: icmp_seq=3 ttl=118 time=6.13 ms
         64 bytes from 8.8.8.8: icmp_seq=4 ttl=118 time=6.11 ms
         ...
+
     * If everything goes well, you are ready to update your system and install 
       new applications for beagleconnect.
 
-Note: If you are facing some issue during boot then you can try debugging the 
-boot session with a USB to serial interface cable such as those made by FTDI 
-plugged into J10 with the black wire of the FTDI cable toward the Ethernet 
-connector. Application like tio/minicom/putty can be used to make the connection 
-establishment procedure easy. 
+.. note:
 
-TODO: Simplify and elaborate on this section, add boot session debugging walkthrough
+    If you are facing some issue during boot then you can try debugging the 
+    boot session with a USB to serial interface cable such as those made by FTDI 
+    plugged into J10 with the black wire of the FTDI cable toward the Ethernet 
+    connector. Application like tio/minicom/putty can be used to make the connection 
+    establishment procedure easy. 
 
-Install Zephyr development tools on BeagleBone Green Gateway
-============================================================
+.. note:
 
-#. Update the system.
-    .. code-block:: bash
-        
-        sudo apt update
-
-#. Install all BeagleConnect™ management software.
-    .. code-block:: bash
+   #TODO#: Simplify and elaborate on this section, add boot session debugging walkthrough
 
-        sudo apt install -y \
-        beagleconnect beagleconnect-msp430 \
-        git vim \
-        build-essential \
-        cmake ninja-build gperf \
-        ccache dfu-util device-tree-compiler \
-        make gcc libsdl2-dev \
-        libxml2-dev libxslt-dev libssl-dev libjpeg62-turbo-dev \
-        gcc-arm-none-eabi libnewlib-arm-none-eabi \
-        libtool-bin pkg-config autoconf automake libusb-1.0-0-dev \
-        python3-dev python3-pip python3-setuptools python3-tk python3-wheel
-
-    .. code-block:: bash
-
-        echo "export PATH=$PATH:$HOME/.local/bin" >> $HOME/.bashrc
-
-    .. code-block:: bash
-
-        source $HOME/.bashrc
-
-#. Reboot
-    .. code-block:: bash
-
-        sudo reboot
-
-#. Install BeagleConnect™ flashing software
-    .. code-block:: bash
-
-        pip3 install -U west
-
-#. Reboot
-    .. code-block:: bash
-
-        sudo reboot
+Install Zephyr development tools on BeagleBone Green Gateway
+============================================================
 
 #. Download and setup Zephyr for BeagleConnect™
     .. code-block:: bash
@@ -193,32 +208,37 @@ Build applications for BeagleConnect Freedom on BeagleBone Green Gateway
 Now you can build various Zephyr applications
 
 #. Change directory to BeagleConnect Freedom zephyr repository.
+
     .. code-block:: bash
 
         cd $HOME/bcf-zephyr
         
 #. Build blinky example
-    .. code-block:: bash
-        west build -d build/blinky zephyr/samples/basic/blinky
 
+    .. code-block:: bash
 
+        west build -d build/blinky zephyr/samples/basic/blinky
 
 #. TODO
+
     .. code-block:: bash
 
         west build -d build/sensortest zephyr/samples/boards/beagle_bcf/sensortest -- -DOVERLAY_CONFIG=overlay-subghz.conf
 
 #. TODO
+
     .. code-block:: bash
 
         west build -d build/wpanusb modules/lib/wpanusb_bc -- -DOVERLAY_CONFIG=overlay-subghz.conf
 
 #. TODO
+
     .. code-block:: bash
 
         west build -d build/bcfserial modules/lib/wpanusb_bc -- -DOVERLAY_CONFIG=overlay-bcfserial.conf -DDTC_OVERLAY_FILE=bcfserial.overlay
 
 #. TODO
+
     .. code-block:: bash
 
         west build -d build/greybus modules/lib/greybus/samples/subsys/greybus/net -- -DOVERLAY_CONFIG=overlay-802154-subg.conf

boards/beagleconnect/index.rst

@@ -3,6 +3,10 @@
 BeagleConnect
 ###############
 
+.. important::
+
+   Currently under development
+
 BeagleConnect™ is a revolutionary technology virtually eliminating low-level 
 software development for `IoT <https://en.wikipedia.org/wiki/Internet_of_things>`_ 
 and `IIoT <https://en.wikipedia.org/wiki/Industrial_internet_of_things>`_ 

boards/index.rst

@@ -22,8 +22,13 @@ started.
 
 .. toctree::
    :maxdepth: 1
+   :hidden:
 
    /boards/beaglebone/index
+   /boards/beaglebone/black/index
+   /boards/beaglebone/blue/index
+   /boards/beaglebone/ai/index
+   /boards/beaglebone/ai-64/index
    /boards/pocketbeagle/original/index
    /boards/capes/index
    /boards/beagleconnect/index

books/beaglebone-cookbook/01basics/basics.rst

@@ -170,15 +170,13 @@ Connect your Bone to the Internet and log into it.  From the command line run:
 
 .. code-block::
 
-    bone$ git clone git@github.com:MarkAYoder/BoneCookbook.git
-    bone$ cd BoneCookbook/docs
+    bone$ git clone https://git.beagleboard.org/beagleboard/beaglebone-cookbook-code
+    bone$ cd beaglebone-cookbook-code
     bone$ ls
 
 You can look around from the command line, or explore from Visual Sudio Code. 
 If you ar using VSC, go to the *File* menu and select *Open Folder ...* and 
-select BoneCookbook/docs. Then explore.   You'll find there is a directory 
-for each chapter and most chapters have a *code* directory for the sample 
-scripts and a *figures* directory for the figures.  
+select beaglebone-cookbook-code. Then explore.
 
 .. _basics_wire_breadboard:
 

books/beaglebone-cookbook/02sensors/code/GPS.js

-#!/usr/bin/env node
-// Install with: npm install nmea
-
-// Need to add exports.serialParsers = m.module.parsers;
-// to the end of /usr/local/lib/node_modules/bonescript/serial.js
-
-var b = require('bonescript');
-var nmea = require('nmea');
-
-var port = '/dev/ttyO4';
-var options = {
-    baudrate: 9600,
-    parser: b.serialParsers.readline("\n")
-};
-
-b.serialOpen(port, options, onSerial);
-
-function onSerial(x) {
-    if (x.err) {
-        console.log('***ERROR*** ' + JSON.stringify(x));
-    }
-    if (x.event == 'open') {
-       console.log('***OPENED***');
-    }
-    if (x.event == 'data') {
-        console.log(String(x.data));
-        console.log(nmea.parse(x.data));
-    }
-}

books/beaglebone-cookbook/02sensors/code/analogIn.js

-#!/usr/bin/env node
-//////////////////////////////////////
-//	analogin.js
-// 	Reads the analog value of the light sensor.
-//////////////////////////////////////
-const fs = require("fs");
-const ms = 500;  // Time in milliseconds
-
-const pin = "2";        // light sensor, A2, P9_37
-
-const IIOPATH='/sys/bus/iio/devices/iio:device0/in_voltage'+pin+'_raw';
-
-console.log('Hit ^C to stop');
-
-// Read every 500ms
-setInterval(readPin, ms);
-
-function readPin() {
-    var data = fs.readFileSync(IIOPATH).slice(0, -1);
-    console.log('data = ' + data);
- }
-// Bone  | Pocket | AIN
-// ----- | ------ | --- 
-// P9_39 | P1_19  | 0
-// P9_40 | P1_21  | 1
-// P9_37 | P1_23  | 2
-// P9_38 | P1_25  | 3
-// P9_33 | P1_27  | 4
-// P9_36 | P2_35  | 5
-// P9_35 | P1_02  | 6

books/beaglebone-cookbook/02sensors/code/analogIn.py

-#!/usr/bin/env python3
-#//////////////////////////////////////
-#	analogin.py
-# 	Reads the analog value of the light sensor.
-#//////////////////////////////////////
-import time
-import os
-
-pin = "2"        # light sensor, A2, P9_37
-
-IIOPATH='/sys/bus/iio/devices/iio:device0/in_voltage'+pin+'_raw'
-
-print('Hit ^C to stop')
-
-f = open(IIOPATH, "r")
-
-while True:
-    f.seek(0)
-    x = float(f.read())/4096
-    print('{}: {:.1f}%, {:.3f} V'.format(pin, 100*x, 1.8*x), end = '\r')
-    time.sleep(0.1)
-
-# // Bone  | Pocket | AIN
-# // ----- | ------ | --- 
-# // P9_39 | P1_19  | 0
-# // P9_40 | P1_21  | 1
-# // P9_37 | P1_23  | 2
-# // P9_38 | P1_25  | 3
-# // P9_33 | P1_27  | 4
-# // P9_36 | P2_35  | 5
-# // P9_35 | P1_02  | 6

books/beaglebone-cookbook/02sensors/code/audio.asoundrc

-pcm.!default {
-  type plug
-  slave {
-    pcm "hw:1,0"
-  }
-}
-ctl.!default {
-  type hw
-  card 1
-}

books/beaglebone-cookbook/02sensors/code/audio.js

-#!/usr/bin/node
-// 'childprocess' help at:
-// http://nodejs.org/api/child_process.html\
-//                    #child_process_child_process_spawn_command_args_options
-"use strict";
-
-var b = require('bonescript'),
-    spawn = require('child_process').spawn;
-
-var audioRate = 48000,
-    bufferSize = 4800,
-    format = "S16_LE";  // 16-bit signed, little endian
-    
-var audioIn = spawn(
-           "/usr/bin/arecord",
-           [
-            "-c2", "-r"+audioRate, "-f"+format, "-traw", 
-            "--buffer-size="+bufferSize, "--period-size="+bufferSize, "-N"
-           ]
-        );
-        
- var audioOut = spawn(
-           "/usr/bin/aplay",
-           [
-            "-c2", "-r"+audioRate, "-f"+format, "-traw", 
-            "--buffer-size="+bufferSize, "--period-size="+bufferSize, "-N"
-           ]
-        );     
-    
-    audioIn.stdout.on('data', function(data) {
-        audioOut.stdin.write(data);
-    });
-    
-    audioIn.on('close', function(code) {
-        if(code !== 0) {
-            console.log('arecord process exited with code: ' + code);
-            audioOut.stdin.end();
-        }
-    })
-    
-    audioOut.on('close', function(code) {
-        if(code !== 0) {
-            console.log('aplay process exited with code: ' + code);
-        }
-    })
-    
\ No newline at end of file

books/beaglebone-cookbook/02sensors/code/bone_eqep2b.dts

-/*
- * Copyright (C) 2013 Nathaniel R. Lewis - http://nathanielrlewis.com/
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- * 
- * Enable eQEP2 on the Beaglebone White and Black
- * These pins don't conflict with the HDMI
- */
-/dts-v1/;
-/plugin/;
-
-/ {
-    compatible = "ti,beaglebone", "ti,beaglebone-black";
-
-    /* identification */
-    part-number = "bone_eqep2";
-    version     = "00A0";
-
-    fragment@0 {
-        target = <&am33xx_pinmux>;
-        __overlay__ {
-            pinctrl_eqep2: pinctrl_eqep2_pins {
-                pinctrl-single,pins = <					 				   
-		          0x038 0x24  /* P8_16 = GPIO2_12 = EQEP2_index, MODE4 */
-		          0x03C 0x24  /* P8_15 = GPIO2_13 = EQEP2_strobe, MODE4 */
-		          0x030 0x34  /* P8_12 = GPIO2_10 = EQEP2A_in, MODE4 */
-		          0x034 0x34  /* P8_11 = GPIO2_11 = EQEP2B_in, MODE4 */
-                >;
-            };
-        };
-    };
-    
-    fragment@1 {
-        target = <&epwmss2>;
-        __overlay__ {
-            status = "okay";
-        };
-    };
-    
-    fragment@2 {
-    	target = <&eqep2>;
-    	__overlay__ {
-        pinctrl-names = "default";
-        pinctrl-0 = <&pinctrl_eqep2>;
-        count_mode = < 0 >;  
-        /* 0 - Quadrature mode, normal 90 phase offset cha & chb.  
-           1 - Direction mode.  cha input = clock, chb input = direction  */
-        swap_inputs = < 0 >; /* Are chan A & chan B swapped? (0-no,1-yes) */
-          invert_qa = < 1 >;   /* Should we invert the channel A input?  */
-          invert_qb = < 1 >;   /* Should we invert the channel B input? 
-                These are inverted because my encoder outputs drive transistors 
-                that pull down the pins */
-          invert_qi = < 0 >;   /* Should we invert the index input? */
-          invert_qs = < 0 >;   /* Should we invert the strobe input? */
-        
-        status = "okay";
-    	};
-    };
-};