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add touchscreen calibrator example
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‎examples/touch_calibrator_built_in.py

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# SPDX-FileCopyrightText: 2022 Cedar Grove Maker Studios
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# SPDX-License-Identifier: MIT
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"""
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touch_calibrator_built_in.py 2022-01-21 v2.1
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Author(s): JG for Cedar Grove Maker Studios
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On-screen touchscreen calibrator for built-in displays.
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When the test screen appears, use a stylus to swipe to the four edges
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of the visible display area. As the screen is calibrated, the small red
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square tracks the stylus tip (REPL_ONLY=False). Minimum and maximum
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calibration values will display on the screen and in the REPL. The calibration
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tuple can be copied and pasted into the calling code's touchscreen
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instantiation statement.
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DISPLAY_ROTATION: Display rotation value in degrees. Only values of
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None, 0, 90, 180, and 270 degrees are accepted. Defaults to None, the
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previous orientation of the display.
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REPL_ONLY: If False, calibration values are shown graphically on the screen
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and printed to the REPL. If True, the values are only printed to the REPL.
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Default value is False.
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"""
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import time
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import board
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import displayio
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import vectorio
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import terminalio
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from adafruit_display_text.label import Label
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import adafruit_touchscreen
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from simpleio import map_range
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# Operational parameters:
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DISPLAY_ROTATION = 0 # Specify 0, 90, 180, or 270 degrees
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REPL_ONLY = False # True to disable graphics
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# pylint: disable=too-few-public-methods
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class Colors:
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"""A collection of colors used for graphic objects."""
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BLUE_DK = 0x000060 # Screen fill
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RED = 0xFF0000 # Boundary
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WHITE = 0xFFFFFF # Text
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# Instantiate the built-in display.
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display = board.DISPLAY
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# Check rotation value and update display.
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# Always set rotation before instantiating the touchscreen.
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if DISPLAY_ROTATION is not None and DISPLAY_ROTATION in (0, 90, 180, 270):
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display.rotation = DISPLAY_ROTATION
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else:
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print("Warning: invalid rotation value -- defalting to zero")
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display.rotation = 0
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time.sleep(1)
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# Activate the display graphics unless REPL_ONLY=True.
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if not REPL_ONLY:
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display_group = displayio.Group()
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display.show(display_group)
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# Instantiate touch screen without calibration or display size parameters
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if display.rotation == 0:
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ts = adafruit_touchscreen.Touchscreen(
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board.TOUCH_XL,
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board.TOUCH_XR,
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board.TOUCH_YD,
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board.TOUCH_YU,
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# calibration=((5200, 59000), (5250, 59500)),
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# size=(board.DISPLAY.width, board.DISPLAY.height),
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)
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elif display.rotation == 90:
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ts = adafruit_touchscreen.Touchscreen(
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board.TOUCH_YU,
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board.TOUCH_YD,
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board.TOUCH_XL,
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board.TOUCH_XR,
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# calibration=((5250, 59500), (5200, 59000)),
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# size=(board.DISPLAY.width, board.DISPLAY.height),
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)
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elif display.rotation == 180:
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ts = adafruit_touchscreen.Touchscreen(
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board.TOUCH_XR,
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board.TOUCH_XL,
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board.TOUCH_YU,
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board.TOUCH_YD,
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# calibration=((5200, 59000), (5250, 59500)),
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# size=(board.DISPLAY.width, board.DISPLAY.height),
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)
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elif display.rotation == 270:
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ts = adafruit_touchscreen.Touchscreen(
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board.TOUCH_YD,
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board.TOUCH_YU,
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board.TOUCH_XR,
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board.TOUCH_XL,
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# calibration=((5250, 59500), (5200, 59000)),
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# size=(board.DISPLAY.width, board.DISPLAY.height),
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)
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else:
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raise ValueError("Rotation value must be 0, 90, 180, or 270")
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# Define the graphic objects if REPL_ONLY = False.
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if not REPL_ONLY:
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# Define the text graphic objects
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font_0 = terminalio.FONT
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coordinates = Label(
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font=font_0,
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text="calib: ((x_min, x_max), (y_min, y_max))",
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color=Colors.WHITE,
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)
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coordinates.anchor_point = (0.5, 0.5)
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coordinates.anchored_position = (
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board.DISPLAY.width // 2,
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board.DISPLAY.height // 4,
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)
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display_rotation = Label(
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font=font_0,
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text="rotation: " + str(display.rotation),
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color=Colors.WHITE,
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)
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display_rotation.anchor_point = (0.5, 0.5)
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display_rotation.anchored_position = (
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board.DISPLAY.width // 2,
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board.DISPLAY.height // 4 - 30,
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)
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# Define graphic objects for the screen fill, boundary, and touch pen.
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target_palette = displayio.Palette(1)
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target_palette[0] = Colors.BLUE_DK
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screen_fill = vectorio.Rectangle(
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pixel_shader=target_palette,
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x=2,
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y=2,
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width=board.DISPLAY.width - 4,
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height=board.DISPLAY.height - 4,
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)
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target_palette = displayio.Palette(1)
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target_palette[0] = Colors.RED
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boundary = vectorio.Rectangle(
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pixel_shader=target_palette,
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x=0,
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y=0,
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width=board.DISPLAY.width,
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height=board.DISPLAY.height,
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)
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pen = vectorio.Rectangle(
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pixel_shader=target_palette,
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x=board.DISPLAY.width // 2,
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y=board.DISPLAY.height // 2,
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width=10,
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height=10,
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)
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display_group.append(boundary)
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display_group.append(screen_fill)
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display_group.append(pen)
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display_group.append(coordinates)
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display_group.append(display_rotation)
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# pylint: disable=invalid-name
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# Reset x and y values to raw touchscreen mid-point before measurement.
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x_min = x_max = y_min = y_max = 65535 // 2
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print("Touchscreen Calibrator")
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print(" Use a stylus to swipe slightly beyond the")
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print(" four edges of the visible display area.")
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print(" ")
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print(f" display rotation: {display.rotation} degrees")
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print(" Calibration values follow:")
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print(" ")
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while True:
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time.sleep(0.100)
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touch = ts.touch_point # Check for touch
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if touch:
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if not REPL_ONLY:
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pen.x = int(map_range(touch[0], x_min, x_max, 0, board.DISPLAY.width)) - 5
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pen.y = int(map_range(touch[1], y_min, y_max, 0, board.DISPLAY.height)) - 5
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# Remember minimum and maximum values for the calibration tuple.
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x_min = min(x_min, touch[0])
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x_max = max(x_max, touch[0])
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y_min = min(y_min, touch[1])
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y_max = max(y_max, touch[1])
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# Show the calibration tuple.
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print(f"(({x_min}, {x_max}), ({y_min}, {y_max}))")
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if not REPL_ONLY:
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coordinates.text = f"calib: (({x_min}, {x_max}), ({y_min}, {y_max}))"

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