.. 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!

.. _2.1.5_py:

2.1.5 Tilt Switch
=================

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

This is a ball tilt-switch with a metal ball inside. It is used to
detect inclinations of a small angle.

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

In this project, we need the following components. 

.. image:: ../img/list_2.1.3_tilt_switch.png

It's definitely convenient to buy a whole kit, here's the link: 

.. list-table::
    :widths: 20 20 20
    :header-rows: 1

    *   - Name	
        - ITEMS IN THIS KIT
        - LINK
    *   - Raphael Kit
        - 337
        - |link_Raphael_kit|

You can also buy them separately from the links below.

.. list-table::
    :widths: 30 20
    :header-rows: 1

    *   - COMPONENT INTRODUCTION
        - PURCHASE LINK

    *   - :ref:`cpn_gpio_board`
        - |link_gpio_board_buy|
    *   - :ref:`cpn_breadboard`
        - |link_breadboard_buy|
    *   - :ref:`cpn_wires`
        - |link_wires_buy|
    *   - :ref:`cpn_resistor`
        - |link_resistor_buy|
    *   - :ref:`cpn_led`
        - |link_led_buy|
    *   - :ref:`cpn_tilt_switch`
        - \-

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

.. image:: ../img/image307.png


.. image:: ../img/image308.png


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

**Step 1:** Build the circuit.

.. image:: ../img/image169.png

**Step 2:** Change directory.

.. raw:: html

   <run></run>

.. code-block:: 

    cd ~/raphael-kit/python/

**Step 3:** Run.

.. raw:: html

   <run></run>

.. code-block:: 

    sudo python3 2.1.5_Tilt.py

Place the tilt vertically, and the green LED will turns on. If you
tilt it, "Tilt!" will be printed on the screen and the red LED will
turns on. Place it vertically again, and the green LED will lights on.

**Code**

.. note::

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


.. raw:: html

    <run></run>

.. code-block:: python

    import RPi.GPIO as GPIO

    TiltPin = 17
    Gpin   = 27
    Rpin   = 22

    def setup():
        GPIO.setmode(GPIO.BCM)       # Numbers GPIOs by physical location
        GPIO.setup(Gpin, GPIO.OUT)     # Set Green Led Pin mode to output
        GPIO.setup(Rpin, GPIO.OUT)     # Set Red Led Pin mode to output
        GPIO.setup(TiltPin, GPIO.IN, pull_up_down=GPIO.PUD_UP)    # Set BtnPin's mode is input, and pull up to high level(3.3V)
        GPIO.add_event_detect(TiltPin, GPIO.BOTH, callback=detect, bouncetime=200)

    def Led(x):
        if x == 0:
            GPIO.output(Rpin, 1)
            GPIO.output(Gpin, 0)
        if x == 1:
            GPIO.output(Rpin, 0)
            GPIO.output(Gpin, 1)

    def Print(x):
        if x == 0:
            print ('    *************')
            print ('    *   Tilt!   *')
            print ('    *************')

    def detect(chn):
        Led(GPIO.input(TiltPin))
        Print(GPIO.input(TiltPin))

    def loop():
        while True:
            pass

    def destroy():
        GPIO.output(Gpin, GPIO.HIGH)       # Green led off
        GPIO.output(Rpin, GPIO.HIGH)       # Red led off
        GPIO.cleanup()                     # Release resource

    if __name__ == '__main__':     # Program start from here
        setup()
        try:
            loop()
        except KeyboardInterrupt:  # When 'Ctrl+C' is pressed, the program destroy() will be  executed.
            destroy()

**Code Explanation**

.. code-block:: python

    GPIO.add_event_detect(TiltPin, GPIO.BOTH, callback=detect, bouncetime=200)

Set up a detect on TiltPin, and callback function to detect.

.. code-block:: python

    def Led(x):
        if x == 0:
            GPIO.output(Rpin, 1)
            GPIO.output(Gpin, 0)
        if x == 1:
            GPIO.output(Rpin, 0)
            GPIO.output(Gpin, 1)

Define a function Led() to turn the two LEDs on or off. If x=0, the red
LED lights up; otherwise, the green LED will be lit.

.. code-block:: python

    def Print(x):
        if x == 0:
            print ('    *************')
            print ('    *   Tilt!   *')
            print ('    *************')

Create a function, Print() to print the characters above on the screen.

.. code-block:: python

    def detect(chn):
        Led(GPIO.input(TiltPin))
        Print(GPIO.input(TiltPin))

Define a callback function for tilt callback. Get the read value of the
tilt switch then the function Led() controls the turning on or off of
the two LEDs that is depended on the read value of the tilt switch.

Phenomenon Picture
------------------

.. image:: ../img/image170.jpeg