This example creates two lines of scrolling text on a 64x32 matrix. 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.
Because each letter is set to a different color, this example doesn't use the adafruit_display_text library.
To customize the text, simply make sure you keep the lines in pairs of equal length, and don't miss the comma at the end of each line.
# SPDX-FileCopyrightText: 2020 Jeff Epler for Adafruit Industries
#
# SPDX-License-Identifier: MIT
# This example implements a rainbow colored scroller, in which each letter
# has a different color. This is not possible with
# Adafruit_Circuitpython_Display_Text, where each letter in a label has the
# same color
#
# This demo also supports only ASCII characters and the built-in font.
# See the simple_scroller example for one that supports alternative fonts
# and characters, but only has a single color per label.
import array
from rainbowio import colorwheel
import board
import displayio
import framebufferio
import rgbmatrix
import terminalio
displayio.release_displays()
matrix = rgbmatrix.RGBMatrix(
width=64, height=32, bit_depth=3,
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)
display = framebufferio.FramebufferDisplay(matrix, auto_refresh=False)
# Create a tilegrid with a bunch of common settings
def tilegrid(palette):
return displayio.TileGrid(
bitmap=terminalio.FONT.bitmap, pixel_shader=palette,
width=1, height=1, tile_width=6, tile_height=12, default_tile=32)
g = displayio.Group()
# We only use the built in font which we treat as being 7x14 pixels
linelen = (64//7)+2
# prepare the main groups
l1 = displayio.Group()
l2 = displayio.Group()
g.append(l1)
g.append(l2)
display.root_group = g
l1.y = 1
l2.y = 16
# Prepare the palettes and the individual characters' tiles
sh = [displayio.Palette(2) for _ in range(linelen)]
tg1 = [tilegrid(shi) for shi in sh]
tg2 = [tilegrid(shi) for shi in sh]
# Prepare a fast map from byte values to
charmap = array.array('b', [terminalio.FONT.get_glyph(32).tile_index]) * 256
for ch in range(256):
glyph = terminalio.FONT.get_glyph(ch)
if glyph is not None:
charmap[ch] = glyph.tile_index
# Set the X coordinates of each character in label 1, and add it to its group
for idx, gi in enumerate(tg1):
gi.x = 7 * idx
l1.append(gi)
# Set the X coordinates of each character in label 2, and add it to its group
for idx, gi in enumerate(tg2):
gi.x = 7 * idx
l2.append(gi)
# These pairs of lines should be the same length
lines = [
b"This scroller is brought to you by CircuitPython & PROTOMATTER",
b" .... . .-.. .-.. --- / .--. .-. --- - --- -- .- - - . .-.",
b"Greetz to ... @PaintYourDragon @v923z @adafruit ",
b" @danh @ladyada @kattni @tannewt all showers & tellers",
b"New York Strong Wash Your Hands ",
b" Flatten the curve Stronger Together",
]
even_lines = lines[0::2]
odd_lines = lines[1::2]
# Scroll a top text and a bottom text
def scroll(t, b):
# Add spaces to the start and end of each label so that it goes from
# the far right all the way off the left
sp = b' ' * linelen
t = sp + t + sp
b = sp + b + sp
maxlen = max(len(t), len(b))
# For each whole character position...
for i in range(maxlen-linelen):
# Set the letter displayed at each position, and its color
for j in range(linelen):
sh[j][1] = colorwheel(3 * (2*i+j))
tg1[j][0] = charmap[t[i+j]]
tg2[j][0] = charmap[b[i+j]]
# And then for each pixel position, move the two labels
# and then refresh the display.
for j in range(7):
l1.x = -j
l2.x = -j
display.refresh(minimum_frames_per_second=0)
# Repeatedly scroll all the pairs of lines
while True:
for e, o in zip(even_lines, odd_lines):
scroll(e, o)
