.. note::

    Hello, welcome to the SunFounder Raspberry Pi & Arduino & ESP32 Enthusiasts Community on Facebook! Dive deeper into Raspberry Pi, Arduino, and ESP32 with fellow enthusiasts.

    **Why Join?**

    - **Expert Support**: Solve post-sale issues and technical challenges with help from our community and team.
    - **Learn & Share**: Exchange tips and tutorials to enhance your skills.
    - **Exclusive Previews**: Get early access to new product announcements and sneak peeks.
    - **Special Discounts**: Enjoy exclusive discounts on our newest products.
    - **Festive Promotions and Giveaways**: Take part in giveaways and holiday promotions.

    👉 Ready to explore and create with us? Click [|link_sf_facebook|] and join today!

.. _py_pi5_pir:

2.2.4 PIR
===========

Introduction
------------

In this project, we will make a device by using the human body infrared
pyroelectric sensors. When someone gets closer to the LED, the LED will
turn on automatically. If not, the light will turn off. This infrared
motion sensor is a kind of sensor that can detect the infrared emitted
by human and animals.

Required Components
------------------------------

In this project, we need the following components. 

.. image:: ../python_pi5/img/2.2.4_pir_list.png

.. raw:: html

   <br/>


Schematic Diagram
-----------------

.. image:: ../python_pi5/img/2.2.4_pir_schematic.png


Experimental Procedures
-----------------------

**Step 1:** Build the circuit.

.. image:: ../python_pi5/img/2.2.4_pir_circuit.png

**Step 2:** Go to the folder of the code.

.. raw:: html

   <run></run>

.. code-block::

    cd ~/davinci-kit-for-raspberry-pi/python-pi5

**Step 3:** Run the executable file.

.. raw:: html

   <run></run>

.. code-block::

    sudo python3 2.2.4_PIR.py

After the code runs, PIR detects surroundings and let RGB LED glow yellow if it senses someone walking by. 

There are two potentiometers on the PIR module: one is to adjust sensitivity and the other is to adjust the detection distance. To make the PIR module work better, you You need to turn both of them counterclockwise to the end.

.. image:: ../python_pi5/img/2.2.4_PIR_TTE.png
    :width: 400
    :align: center

.. warning::

    If there is an error prompt  ``RuntimeError: Cannot determine SOC peripheral base address``, please refer to :ref:`faq_soc` 

**Code**

.. note::

    You can **Modify/Reset/Copy/Run/Stop** the code below. But before that, you need to go to  source code path like ``davinci-kit-for-raspberry-pi/python-pi5``. After modifying the code, you can run it directly to see the effect.


.. raw:: html

    <run></run>

.. code-block:: python

   #!/usr/bin/env python3
   from gpiozero import RGBLED, MotionSensor
   from time import sleep

   # Initialize RGB LED and PIR motion sensor using GPIO Zero library
   led = RGBLED(red=18, green=27, blue=22)  # RGB LED connected to GPIO pins 18 (Red), 27 (Green), 22 (Blue)
   pir = MotionSensor(17)  # PIR sensor connected to GPIO pin 17

   try:
       # Continuously monitor for motion and update LED color
       while True:
           if pir.motion_detected:  # Check for motion detected by PIR sensor
               led.color = (1, 1, 0)  # Set LED color to yellow (Red + Green)
           else:
               led.color = (0, 0, 1)  # Set LED color to blue (only Blue)
           sleep(0.1)  # Short delay to reduce CPU load

   except KeyboardInterrupt:
       # Handle KeyboardInterrupt (Ctrl+C) to exit the loop gracefully
       pass


**Code Explanation**

#. Imports the ``RGBLED`` class for controlling an RGB LED and the ``MotionSensor`` class for motion detection from the GPIO Zero library. Also imports the ``sleep`` function for creating delays.

   .. code-block:: python

       #!/usr/bin/env python3
       from gpiozero import RGBLED, MotionSensor
       from time import sleep

#. Initializes an RGB LED with red, green, and blue components connected to GPIO pins 18, 27, and 22, respectively. Also, initializes a PIR sensor on GPIO pin 17.

   .. code-block:: python

       # Initialize RGB LED and PIR motion sensor using GPIO Zero library
       led = RGBLED(red=18, green=27, blue=22)  # RGB LED connected to GPIO pins 18 (Red), 27 (Green), 22 (Blue)
       pir = MotionSensor(17)  # PIR sensor connected to GPIO pin 17

#. The program enters an infinite loop, continuously checking for motion using the PIR sensor. If motion is detected, the LED is set to yellow (mix of red and green). If no motion is detected, the LED turns blue. A short sleep of 0.1 seconds reduces CPU load.

   .. code-block:: python

       try:
           # Continuously monitor for motion and update LED color
           while True:
               if pir.motion_detected:  # Check for motion detected by PIR sensor
                   led.color = (1, 1, 0)  # Set LED color to yellow (Red + Green)
               else:
                   led.color = (0, 0, 1)  # Set LED color to blue (only Blue)
               sleep(0.1)  # Short delay to reduce CPU load

       except KeyboardInterrupt:
           # Handle KeyboardInterrupt (Ctrl+C) to exit the loop gracefully
           pass