adding displayio example

Author: jposada202020

docs/examples.rst

@@ -24,3 +24,12 @@ Be alerted when the measured value passes a high or low threshold
 .. literalinclude:: ../examples/ltr390_alert_test.py
     :caption: examples/ltr390_alert_test.py
     :linenos:
+
+DisplayIO Simpletest
+---------------------
+
+This is a simple test for boards with built-in display.
+
+.. literalinclude:: ../examples/ltr390_displayio_simpletest.py
+    :caption: examples/ltr390_displayio_simpletest.py
+    :linenos:

examples/ltr390_displayio_simpletest.py

@@ -0,0 +1,51 @@
+# SPDX-FileCopyrightText: 2024 Tim Cocks for Adafruit Industries
+# SPDX-FileCopyrightText: 2025 Jose D. Montoya
+#
+# SPDX-License-Identifier: MIT
+
+import time
+import board
+from adafruit_display_text.bitmap_label import Label
+from terminalio import FONT
+from displayio import Group
+import adafruit_ltr390
+
+# Simple demo of using the built-in display.
+# create a main_group to hold anything we want to show on the display.
+main_group = Group()
+# Initialize I2C bus and sensor.
+i2c = board.I2C()  # uses board.SCL and board.SDA
+ltr = adafruit_ltr390.LTR390(i2c)
+
+
+# Create Label(s) to show the readings. If you have a very small
+# display you may need to change to scale=1.
+display_output_light = Label(FONT, text="", scale=2)
+display_output_lux = Label(FONT, text="", scale=2)
+
+# place the label(s) in the middle of the screen with anchored positioning
+display_output_light.anchor_point = (0, 0)
+display_output_light.anchored_position = (
+    4,
+    board.DISPLAY.height // 2 - 60,
+)
+display_output_lux.anchor_point = (0, 0)
+display_output_lux.anchored_position = (
+    4,
+    board.DISPLAY.height // 2 - 40,
+)
+
+# add the label(s) to the main_group
+main_group.append(display_output_light)
+main_group.append(display_output_lux)
+
+# set the main_group as the root_group of the built-in DISPLAY
+board.DISPLAY.root_group = main_group
+
+# begin main loop
+while True:
+    # update the text of the label(s) to show the sensor readings
+    display_output_light.text = f"Ambient Light: {ltr.light:.2f}"
+    display_output_lux.text = f"Lux: {ltr.lux:.2f}"
+    # wait for a bit
+    time.sleep(0.5)