This example creates two lines of scrolling text on a 64x32 matrix using CircuitPython Display Text. It's designed for the FeatherWing M4 Express, but you can adapt it to other boards by changing the lines that create the RGBMatrix object. We've thoroughly commented this example so it's a great place to start if you're not familiar with displayio.

For this example make sure to install the following library:

If you want to customize the example to use a different font, you'll also need

Here's how the code will work:

  • Create the RGBMatrix and FramebufferDisplay objects
  • Create the two text labels to scroll
  • Put them in a Group, and then show that Group
  • Repeatedly scroll each label to the left, returning it to the far right hand side when it has gone all the way
# This example implements a simple two line scroller using
# Adafruit_CircuitPython_Display_Text. Each line has its own color
# and it is possible to modify the example to use other fonts and non-standard
# characters.

import adafruit_display_text.label
import board
import displayio
import framebufferio
import rgbmatrix
import terminalio

# If there was a display before (protomatter, LCD, or E-paper), release it so
# we can create ours
displayio.release_displays()

# This next call creates the RGB Matrix object itself. It has the given width
# and height. bit_depth can range from 1 to 6; higher numbers allow more color
# shades to be displayed, but increase memory usage and slow down your Python
# code. If you just want to show primary colors plus black and white, use 1.
# Otherwise, try 3, 4 and 5 to see which effect you like best.
#
# These lines are for the Feather M4 Express. If you're using a different board,
# check the guide to find the pins and wiring diagrams for your board.
# If you have a matrix with a different width or height, change that too.
# If you have a 16x32 display, try with just a single line of text.
matrix = rgbmatrix.RGBMatrix(
    width=64, height=32, bit_depth=1,
    rgb_pins=[board.D6, board.D5, board.D9, board.D11, board.D10, board.D12],
    addr_pins=[board.A5, board.A4, board.A3, board.A2],
    clock_pin=board.D13, latch_pin=board.D0, output_enable_pin=board.D1)

# Associate the RGB matrix with a Display so that we can use displayio features
display = framebufferio.FramebufferDisplay(matrix, auto_refresh=False)

# Create two lines of text to scroll. Besides changing the text, you can also
# customize the color and font (using Adafruit_CircuitPython_Bitmap_Font).
# To keep this demo simple, we just used the built-in font.
# The Y coordinates of the two lines were chosen so that they looked good
# but if you change the font you might find that other values work better.
line1 = adafruit_display_text.label.Label(
    terminalio.FONT,
    color=0xff0000,
    text="This scroller is brought to you by CircuitPython RGBMatrix")
line1.x = display.width
line1.y = 8

line2 = adafruit_display_text.label.Label(
    terminalio.FONT,
    color=0x0080ff,
    text="Hello to all CircuitPython contributors worldwide <3")
line2.x = display.width
line2.y = 24

# Put each line of text into a Group, then show that group.
g = displayio.Group()
g.append(line1)
g.append(line2)
display.show(g)

# This function will scoot one label a pixel to the left and send it back to
# the far right if it's gone all the way off screen. This goes in a function
# because we'll do exactly the same thing with line1 and line2 below.
def scroll(line):
    line.x = line.x - 1
    line_width = line.bounding_box[2]
    if line.x < -line_width:
        line.x = display.width

# This function scrolls lines backwards.  Try switching which function is
# called for line2 below!
def reverse_scroll(line):
    line.x = line.x + 1
    line_width = line.bounding_box[2]
    if line.x >= display.width:
        line.x = -line_width

# You can add more effects in this loop. For instance, maybe you want to set the
# color of each label to a different value.
while True:
    scroll(line1)
    scroll(line2)
    #reverse_scroll(line2)
    display.refresh(minimum_frames_per_second=0)

This guide was first published on Apr 20, 2020. It was last updated on Apr 20, 2020.

This page (Example: Simple two-line text scroller) was last updated on Nov 06, 2020.