Add Touchscreen Calibrator Example

examples/touchscreen_calibrator_built_in.py

@@ -0,0 +1,199 @@
+# SPDX-FileCopyrightText: 2022 Cedar Grove Maker Studios
+# SPDX-License-Identifier: MIT
+
+"""
+touch_calibrator_built_in.py  2022-05-27 v2.2
+
+Author(s): JG for Cedar Grove Maker Studios
+
+On-screen touchscreen calibrator for built-in displays.
+
+When the test screen appears, use a stylus to swipe to the four edges
+of the visible display area. As the screen is calibrated, the small red
+square tracks the stylus tip (REPL_ONLY=False). Minimum and maximum
+calibration values will display on the screen and in the REPL. The calibration
+tuple can be copied and pasted into the calling code's touchscreen
+instantiation statement.
+
+DISPLAY_ROTATION: Display rotation value in degrees. Only values of
+None, 0, 90, 180, and 270 degrees are accepted. Defaults to None, the
+previous orientation of the display.
+
+REPL_ONLY: If False, calibration values are shown graphically on the screen
+and printed to the REPL. If True, the values are only printed to the REPL.
+Default value is False.
+"""
+
+import time
+import board
+import displayio
+import vectorio
+import terminalio
+from adafruit_display_text.label import Label
+from simpleio import map_range
+import adafruit_touchscreen
+
+
+# Operational parameters:
+DISPLAY_ROTATION = 0  # Specify 0, 90, 180, or 270 degrees
+REPL_ONLY = False  # True to disable graphics
+
+# pylint: disable=too-few-public-methods
+class Colors:
+    """A collection of colors used for graphic objects."""
+
+    BLUE_DK = 0x000060  # Screen fill
+    RED = 0xFF0000  # Boundary
+    WHITE = 0xFFFFFF  # Text
+
+
+# Instantiate the built-in display
+display = board.DISPLAY
+
+# Check rotation value and update display.
+# Always set rotation before instantiating the touchscreen.
+if DISPLAY_ROTATION is not None and DISPLAY_ROTATION in (0, 90, 180, 270):
+    display.rotation = DISPLAY_ROTATION
+else:
+    print("Warning: invalid rotation value -- defaulting to zero")
+    display.rotation = 0
+    time.sleep(1)
+
+# Activate the display graphics unless REPL_ONLY=True
+if not REPL_ONLY:
+    display_group = displayio.Group()
+    display.show(display_group)
+
+# Instantiate touch screen without calibration or display size parameters
+if display.rotation == 0:
+    ts = adafruit_touchscreen.Touchscreen(
+        board.TOUCH_XL,
+        board.TOUCH_XR,
+        board.TOUCH_YD,
+        board.TOUCH_YU,
+        # calibration=((5200, 59000), (5250, 59500)),
+        # size=(board.DISPLAY.width, board.DISPLAY.height),
+    )
+
+elif display.rotation == 90:
+    ts = adafruit_touchscreen.Touchscreen(
+        board.TOUCH_YU,
+        board.TOUCH_YD,
+        board.TOUCH_XL,
+        board.TOUCH_XR,
+        # calibration=((5250, 59500), (5200, 59000)),
+        # size=(board.DISPLAY.width, board.DISPLAY.height),
+    )
+
+elif display.rotation == 180:
+    ts = adafruit_touchscreen.Touchscreen(
+        board.TOUCH_XR,
+        board.TOUCH_XL,
+        board.TOUCH_YU,
+        board.TOUCH_YD,
+        # calibration=((5200, 59000), (5250, 59500)),
+        # size=(board.DISPLAY.width, board.DISPLAY.height),
+    )
+
+elif display.rotation == 270:
+    ts = adafruit_touchscreen.Touchscreen(
+        board.TOUCH_YD,
+        board.TOUCH_YU,
+        board.TOUCH_XR,
+        board.TOUCH_XL,
+        # calibration=((5250, 59500), (5200, 59000)),
+        # size=(board.DISPLAY.width, board.DISPLAY.height),
+    )
+else:
+    raise ValueError("Rotation value must be 0, 90, 180, or 270")
+
+# Define the graphic objects if REPL_ONLY = False
+if not REPL_ONLY:
+    # Define the text graphic objects
+    font_0 = terminalio.FONT
+
+    coordinates = Label(
+        font=font_0,
+        text="calib: ((x_min, x_max), (y_min, y_max))",
+        color=Colors.WHITE,
+    )
+    coordinates.anchor_point = (0.5, 0.5)
+    coordinates.anchored_position = (
+        board.DISPLAY.width // 2,
+        board.DISPLAY.height // 4,
+    )
+
+    display_rotation = Label(
+        font=font_0,
+        text="rotation: " + str(display.rotation),
+        color=Colors.WHITE,
+    )
+    display_rotation.anchor_point = (0.5, 0.5)
+    display_rotation.anchored_position = (
+        board.DISPLAY.width // 2,
+        board.DISPLAY.height // 4 - 30,
+    )
+
+    # Define graphic objects for the screen fill, boundary, and touch pen
+    target_palette = displayio.Palette(1)
+    target_palette[0] = Colors.BLUE_DK
+    screen_fill = vectorio.Rectangle(
+        pixel_shader=target_palette,
+        x=2,
+        y=2,
+        width=board.DISPLAY.width - 4,
+        height=board.DISPLAY.height - 4,
+    )
+
+    target_palette = displayio.Palette(1)
+    target_palette[0] = Colors.RED
+    boundary = vectorio.Rectangle(
+        pixel_shader=target_palette,
+        x=0,
+        y=0,
+        width=board.DISPLAY.width,
+        height=board.DISPLAY.height,
+    )
+
+    pen = vectorio.Rectangle(
+        pixel_shader=target_palette,
+        x=board.DISPLAY.width // 2,
+        y=board.DISPLAY.height // 2,
+        width=10,
+        height=10,
+    )
+
+    display_group.append(boundary)
+    display_group.append(screen_fill)
+    display_group.append(pen)
+    display_group.append(coordinates)
+    display_group.append(display_rotation)
+
+# pylint: disable=invalid-name
+# Reset x and y values to raw touchscreen mid-point before measurement
+x_min = x_max = y_min = y_max = 65535 // 2
+
+print("Touchscreen Calibrator")
+print("  Use a stylus to swipe slightly beyond the")
+print("  four edges of the visible display area.")
+print(" ")
+print(f"  display rotation: {display.rotation} degrees")
+print("  Calibration values follow:")
+print(" ")
+
+while True:
+    time.sleep(0.100)
+    touch = ts.touch_point  # Check for touch
+    if touch:
+        # Remember minimum and maximum values for the calibration tuple
+        x_min = min(x_min, touch[0])
+        x_max = max(x_max, touch[0])
+        y_min = min(y_min, touch[1])
+        y_max = max(y_max, touch[1])
+
+        # Show the calibration tuple.
+        print(f"(({x_min}, {x_max}), ({y_min}, {y_max}))")
+        if not REPL_ONLY:
+            pen.x = int(map_range(touch[0], x_min, x_max, 0, board.DISPLAY.width)) - 5
+            pen.y = int(map_range(touch[1], y_min, y_max, 0, board.DISPLAY.height)) - 5
+            coordinates.text = f"calib: (({x_min}, {x_max}), ({y_min}, {y_max}))"