Test a builtin display with a grid to check colstart/rowstart and such

board_display_grid_test.py

import board
import displayio
import time
import vectorio

display = board.DISPLAY
splash = displayio.Group(x=0, y=0, scale=1)
display.show(splash)

color_palette = displayio.Palette(2)
color_palette[0] = 0
color_palette[1] = 0xFFFFFF

lines = displayio.Group()
lines.append(vectorio.Rectangle(pixel_shader=color_palette, color_index=1,
    x=0, y=0, width=display.width, height=display.height,
))
lines.append(vectorio.Rectangle(pixel_shader=color_palette, color_index=0,
    x=1, y=1, width=display.width-2, height=display.height-2,
))
for y in range(0, display.height+1, 16):
    lines.append(vectorio.Rectangle(pixel_shader=color_palette,
        width=display.width, height=1, x=0, y=y, color_index=1,
    ))
for x in range(0, display.width+1, 16):
    lines.append(vectorio.Rectangle(pixel_shader=color_palette,
        width=1, height=display.height, x=x, y=0, color_index=1,
    ))

splash.append(lines)

# this must not crash with a "pin in use" error
i2c = board.I2C()

while True:
    time.sleep(1)