add tutorial on create virtual envirnment

README.md

@@ -18,6 +18,9 @@ In the 3-in-1 starter kit, you will find a complete Arduino course to help begin
 
 <a id="update"></a>
 ## Update:
+2024-04-03:
+- Add the tutorial on installing a virtual environment
+
 2024-03-18:
 - Add the video courses
 

docs/source/2.2.7_mfrc522_rfid_module.rst

@@ -161,7 +161,27 @@ to the card.
 
 For Python Language Users
 ^^^^^^^^^^^^^^^^^^^^^^^^^
-**Step 2:** Install the libraries.
+
+**Step 2**: Activating the Virtual Environment.
+
+.. note::
+
+    * Before activation, you need to ensure that you have created a virtual environment, please refer to: :ref:`create_virtual`.
+
+    * Each time you restart the Raspberry Pi, or open a new terminal, you will need to run the following command again to activate the virtual environment.
+
+.. raw:: html
+
+    <run></run>
+
+.. code-block:: shell
+
+    source myenv/bin/activate
+
+Once the virtual environment is activated, you will see the environment name before the command line prompt, indicating you are working within the virtual environment.
+
+
+**Step 3:** Install the libraries.
 
 The ``spidev`` library helps handle interactions with the SPI and is a key component to this tutorial as we need it for the Raspberry Pi to interact with the RFID RC522.
 
@@ -191,8 +211,21 @@ Among them ``MFRC522.py`` is the realization of RFID RC522 interface, this libra
     sudo pip3 install mfrc522
 
 
+**Step 4**: Exiting the Virtual Environment.
 
-**Step 3:** Go to the folder of the code.
+When you have completed your work and wish to exit the virtual environment, simply run:
+
+.. raw:: html
+
+    <run></run>
+
+.. code-block:: shell
+
+    deactivate
+
+This will return you to the system's global Python environment.
+
+**Step 5:** Go to the folder of the code.
 
 .. raw:: html
 
@@ -202,7 +235,7 @@ Among them ``MFRC522.py`` is the realization of RFID RC522 interface, this libra
 
     cd ~/davinci-kit-for-raspberry-pi/python/2.2.7
 
-**Step 4:** Run the executable file.
+**Step 6:** Run the executable file.
 
 .. raw:: html
 
@@ -313,6 +346,6 @@ This function is used to read card data. If the reading is successful, id and te
 This function is used to write information to the card, press ``Enter`` key to finish writing. ``text`` is the information to be written to the card.
 
 Phenomenon Picture
-------------------
+---------------------
 
 .. image:: img/image233.jpeg

docs/source/appendix/appendix.rst

@@ -7,4 +7,5 @@ Appendix
     i2c_configuration
     spi_configuration
     remote_desktop
-    get_ip
+    get_ip
+    create_virtual_environment

docs/source/appendix/create_virtual_environment.rst

@@ -0,0 +1,109 @@
+.. _create_virtual:
+
+Creating a Virtual Environment
+======================================
+When using Raspberry Pi or similar devices, it is recommended to install packages with ``pip`` in a virtual environment. It offers dependency isolation, increases system security, maintains system cleanliness, and facilitates project migration and sharing, simplifying dependency management. These benefits make virtual environments an extremely important and useful tool in Python development.
+
+Below are the steps to create a virtual environment:
+
+**1. Create a virtual environment**
+
+Firstly, you need to ensure that your system has Python installed. Python version 3.3 and later come with the ``venv`` module to create virtual environments, eliminating the need for separate installation. If you are using Python 2 or a version before Python 3.3, you will need to install ``virtualenv``.
+
+* For Python 3:
+
+Python 3.3 and later versions can directly use the ``venv`` module:
+
+.. raw:: html
+
+    <run></run>
+
+.. code-block:: shell
+
+    python3 -m venv myenv
+
+This will create a virtual environment named ``myenv`` in the current directory.
+
+* For Python 2:
+
+If you are still using Python 2, you first need to install ``virtualenv``:
+
+.. raw:: html
+
+    <run></run>
+
+.. code-block:: shell
+
+    pip install virtualenv
+
+Then, create a virtual environment:
+
+.. raw:: html
+
+    <run></run>
+
+.. code-block:: shell
+
+    virtualenv myenv
+
+This also creates a virtual environment named ``myenv`` in the current directory.
+
+**2. Activating the Virtual Environment**
+
+After creating the virtual environment, you need to activate it for use.
+
+.. note::
+
+    Each time you restart the Raspberry Pi, or open a new terminal, you will need to run the following command again to activate the virtual environment.
+
+.. raw:: html
+
+    <run></run>
+
+.. code-block:: shell
+
+    source myenv/bin/activate
+
+Once the virtual environment is activated, you will see the environment name before the command line prompt, indicating you are working within the virtual environment.
+
+
+**3. Installing Dependencies**
+
+With the virtual environment activated, you can use pip to install the required dependencies. For example:
+
+.. raw:: html
+
+    <run></run>
+
+.. code-block:: shell
+
+    pip install requests
+
+This will install the requests library into the current virtual environment, rather than the global environment. This step only needs to be done once.
+
+
+**4. Exiting the Virtual Environment**
+
+When you have completed your work and wish to exit the virtual environment, simply run:
+
+.. raw:: html
+
+    <run></run>
+
+.. code-block:: shell
+
+    deactivate
+
+This will return you to the system's global Python environment.
+
+**5. Deleting the Virtual Environment**
+
+If you no longer need a particular virtual environment, you can simply delete the directory containing the virtual environment:
+
+.. raw:: html
+
+    <run></run>
+
+.. code-block:: shell
+
+    rm -rf myenv

docs/source/appendix/i2c_configuration.rst

@@ -103,12 +103,49 @@ If there is an I2C device connected, the address of the device will be displayed
 
     sudo apt-get install libi2c-dev 
 
-**For Python users:** Install smbus for I2C.
+**For Python users:**
+
+1. Activating the Virtual Environment.
+
+.. note::
+
+    * Before activation, you need to ensure that you have created a virtual environment, please refer to: :ref:`create_virtual`.
+
+    * Each time you restart the Raspberry Pi, or open a new terminal, you will need to run the following command again to activate the virtual environment.
+
+.. raw:: html
+
+    <run></run>
+
+.. code-block:: shell
+
+    source myenv/bin/activate
+
+Once the virtual environment is activated, you will see the environment name before the command line prompt, indicating you are working within the virtual environment.
+
+
+
+2. Install smbus for I2C.
 
 .. raw:: html
 
     <run></run>
 
 .. code-block:: 
 
-    sudo pip3 install smbus2
+    sudo pip3 install smbus2
+
+
+3. Exiting the Virtual Environment.
+
+When you have completed your work and wish to exit the virtual environment, simply run:
+
+.. raw:: html
+
+    <run></run>
+
+.. code-block:: shell
+
+    deactivate
+
+This will return you to the system's global Python environment.