Merge pull request #20 in TIOP/connectedhomeip from feature/SLSTACKSW…

…-31-updates-to-chip-lock-app-readme-march-2021 to connectedhomeip-next

Squashed commit of the following:

commit 87e85f633b28f6a312690718123175ae3b00d9ac
Author: Toby Pan <b-pan@ti.com>
Date:   Thu Mar 11 13:25:39 2021 -0600

    minor tweak

commit 30480152d5015503931be1c14fe754c0494e34a9
Author: Toby Pan <b-pan@ti.com>
Date:   Thu Mar 11 13:22:06 2021 -0600

    added note on environment which uses a different version of python3

commit e78087430ca563fad2e073a9cfd5a60749f2ed30
Author: Toby Pan <b-pan@ti.com>
Date:   Wed Mar 10 23:59:58 2021 -0600

    updates based on collective feedback

examples/lock-app/cc13x2x7_26x2x7/README.md

@@ -62,7 +62,8 @@ advertisements.
 ### Preparation
 
 Some initial setup is necessary for preparing the build environment. This
-section will need to be done when migrating to new versions of the SDK.
+section will need to be done when migrating to new versions of the SDK. This
+guide assumes that the environment is linux based, and recommends Ubuntu 20.04.
 
 -   An engineering SDK from TI is required. Please request access for it
     [here][ti_cc13x2_26x2_r7_chip_request].
@@ -75,7 +76,7 @@ section will need to be done when migrating to new versions of the SDK.
         changes needed.
 
 -   Download and install [SysConfig][sysconfig]
-    ([sysconfig-1.5.0_1397][sysconfig-1.5.0_1397])
+    ([recommended version][sysconfig_recommended])
 
     -   This may have already been installed with your SimpleLink SDK install.
 
@@ -95,11 +96,43 @@ section will need to be done when migrating to new versions of the SDK.
     -   You will have to ensure that the default version of Python 3 is Python
         3.8.
 
+        -   Check python3 version:
+
+        ```
+        $ python3 --version
+        Python 3.8.0
+        ```
+
+        -   If it is not Python 3.8:
+
+        ```
+        $ sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.8 1
+        ```
+
+            -   This may affect your environment in other ways if there was a
+                specific dependency on the prior python3 version (e.g. apt).
+                After completing the build process for this example, you can
+                revert the python3 version, for instance:
+
+                ```
+                $ sudo update-alternatives --config python3
+                There are 2 choices for the alternative python3 (providing /usr/bin/python3).
+
+                  Selection    Path                Priority    Status
+                -------------------------------------------------------------
+                  0            /usr/bin/python3.8   1          auto mode
+                  1            /usr/bin/python3.6   1          manual mode
+                * 2            /usr/bin/python3.8   1          manual mode
+
+                Press <enter> to keep the current choice[*], or type selection number: 1
+                update-alternatives: using /usr/bin/python3.6 to provide /usr/bin/python3 (python3) in manual mode
+                ```
+
 -   Run the bootstrap script to setup the build environment.
 
     ```
     $ cd ~/connectedhomeip
-    $ source ./script/bootstrap.sh
+    $ source ./scripts/bootstrap.sh
 
     ```
 
@@ -112,19 +145,20 @@ Ninja to build the executable.
 
     ```
     $ cd ~/connectedhomeip
-    $ source ./script/activate.sh
+    $ source ./scripts/activate.sh
 
     ```
 
 -   Run the build to produce a default executable. By default on Linux both the
     TI SimpleLink SDK and Sysconfig are located in a `ti` folder in the user's
     home directory, and you must provide the absolute path to them. For example
     `/home/username/ti/simplelink_cc13x2_26x2_sdk_4_40_05_02_eng` and
-    `/home/username/ti/sysconfig_1.6.0`. On Windows the default directory is
-    `C:\ti`
+    `/home/username/ti/sysconfig_1.7.0`. On Windows the default directory is
+    `C:\ti`. Take note of this install path, as it will be used in the next
+    step.
 
     ```
-    $ cd ~/connectedhomeip/examples/lock-app/cc13x2_26x2
+    $ cd ~/connectedhomeip/examples/lock-app/cc13x2x7_26x2x7
     $ export TI_SIMPLELINK_SDK_ROOT=<path-to-simplelink-sdk>
     $ export TI_SYSCONFIG_ROOT=<path-to-sysconfig-sdk>
     $ gn gen out/debug --args="ti_simplelink_sdk_root=\"${TI_SIMPLELINK_SDK_ROOT}\" ti_sysconfig_root=\"${TI_SYSCONFIG_ROOT}\""
@@ -223,8 +257,8 @@ Additionally, we welcome any feedback.
 [simplelink_sdk_4.30.00.54]:
     https://www.ti.com/tool/download/SIMPLELINK-CC13X2-26X2-SDK/4.30.00.54
 [sysconfig]: https://www.ti.com/tool/SYSCONFIG
-[sysconfig-1.5.0_1397]:
-    http://software-dl.ti.com/ccs/esd/sysconfig/sysconfig-1.5.0_1397-setup.run
+[sysconfig_recommended]:
+    https://software-dl.ti.com/ccs/esd/sysconfig/sysconfig-1.7.0_1746-setup.run
 [ti_thread_dnd]:
     https://www.ti.com/wireless-connectivity/thread/design-development.html
 [ti_cc13x2_26x2_r7_chip_request]: https://ti.com/chip_sdk