.. 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!
.. _1.1.6_py:
1.1.6 LED Dot Matrix
=====================
Introduction
--------------------
As the name suggests, an LED dot matrix is a matrix composed of LEDs.
The lighting up and dimming of the LEDs formulate different characters
and patterns.
Required Components
------------------------------
In this project, we need the following components.
.. image:: ../img/list_dot.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_extension_board`
- |link_gpio_board_buy|
* - :ref:`cpn_breadboard`
- |link_breadboard_buy|
* - :ref:`cpn_wires`
- |link_wires_buy|
* - :ref:`cpn_dot_matrix`
- |link_led_matrix_buy|
Schematic Diagram
-----------------------
============ ======== ======== ====
T-Board Name physical wiringPi BCM
SPIMOSI Pin 19 12 MOSI
SPICE0 pin 24 10 CE0
SPISCLK Pin 23 14 SCLK
============ ======== ======== ====
.. image:: ../img/schematic_dot.png
Experimental Procedures
----------------------------
**Step 1:** Build the circuit.
.. image:: ../img/1.1.6fritzing.png
**Step 2:** Turn on the SPI before starting the experiment, refer to :ref:`spi_configuration` for details.
**Step 3:** Install :ref:`Luma.LED_Matrix` module.
**Step 4:** Change directory.
.. raw:: html
.. code-block::
cd ~/raphael-kit/python-pi5
**Step 5:** Runs the ``1.1.6_LedMatrix.py`` Python script using the Python interpreter from the ``my_env`` virtual environment.
.. raw:: html
.. code-block::
sudo ~/my_env/bin/python3 1.1.6_LedMatrix.py
After running the code, the LED Matrix will display a rectangle for two seconds, then the text 'A' for two seconds, and finally scroll to display the text "Hello, Nice to meet you!
**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
.. code-block:: python
from luma.core.interface.serial import spi, noop
from luma.core.render import canvas
from luma.core.virtual import viewport
from luma.led_matrix.device import max7219
from luma.core.legacy import text
from luma.core.legacy.font import proportional, CP437_FONT, LCD_FONT
import time
serial = spi(port=0, device=0, gpio=noop())
device = max7219(serial, rotate=1)
virtual = viewport(device, width=200, height=400)
def displayRectangle():
with canvas(device) as draw:
draw.rectangle(device.bounding_box, outline="white", fill="black")
def displayLetter():
with canvas(device) as draw:
text(draw, (0, 0), "A", fill="white", font=proportional(CP437_FONT))
def scrollToDisplayText():
with canvas(virtual) as draw:
text(draw, (0, 0), "Hello, Nice to meet you!", fill="white", font=proportional(CP437_FONT))
for offset in range(150):
virtual.set_position((offset,0))
time.sleep(0.1)
def main():
while True:
displayRectangle()
time.sleep(2)
displayLetter()
time.sleep(2)
scrollToDisplayText()
def destroy():
pass
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
destroy()
**Code Explanation**
.. code-block:: python
from luma.core.interface.serial import spi, noop
from luma.core.render import canvas
from luma.core.virtual import viewport
from luma.led_matrix.device import max7219
from luma.core.legacy import text
from luma.core.legacy.font import proportional, CP437_FONT, LCD_FONT
import time
Import the relevant libraries, of which ``luma.core`` is a component library that provides a Pillow-compatible canvas for Python 3, as well as other drawing primitives and text rendering features that support small displays on Raspberry Pi and other single-board computers.
You can visit `https://luma-core.readthedocs.io/en/latest/intro.html `_ to learn more.
.. code-block:: python
serial = spi(port=0, device=0, gpio=noop())
device = max7219(serial, rotate=1)
Initialize the ``luma.led_matrix.device.max7219`` class.
.. note::
If you want to modify the display direction of the LED Matrix, you can do so by modifying the value of rotate, where 0 means no rotation, 1 means 90° clockwise rotation, 2 means 180° rotation, and 3 means 270° clockwise rotation.
.. code-block:: python
def displayRectangle():
with canvas(device) as draw:
draw.rectangle(device.bounding_box, outline="white", fill="black")
Display a hollow rectangle in the edge area of the LED Matrix and modify the value of ``fill`` to ``white`` to display a solid rectangle.
.. code-block:: python
def displayLetter():
with canvas(device) as draw:
text(draw, (0, 0), "A", fill="white", font=proportional(CP437_FONT))
An "A" is displayed on the (0, 0) coordinate of the LED Matrix, where ``CP437_FONT`` is a font suitable for 8*8 dot matrix screens.
.. code-block:: python
virtual = viewport(device, width=200, height=400)
There is no way to display a line of text in a single 8x8 LED matrix. We need to use the ``luma.core.virtual.viewport`` method so that the text can be scrolled through the virtual viewport.
.. code-block:: python
def scrollToDisplayText():
with canvas(virtual) as draw:
text(draw, (0, 0), "Hello, Nice to meet you!", fill="white", font=proportional(CP437_FONT))
for offset in range(150):
virtual.set_position((offset,0))
time.sleep(0.1)
``scrollToDisplayText()`` implements "Hello, Nice to meet you!" as a scrolling text on the LED Matrix.
First, we pass virtual as an argument to the ``canvas()`` function, so that we can use the virtual window as the current display window. Then the ``text()`` function displays "Hello, Nice to meet you!" on the LED Matrix.
Using the for loop function, we move the virtual window in the X direction so that we can see the "Hello, Nice to meet you!" text scrolling.
Phenomenon Picture
-----------------------
.. image:: ../img/1.1.6led_dot_matrix.JPG