Merge pull request #2029 from caternuson/knob_sketcher

Add knob sketch code

Author: ladyada

CircuitPython_Knob_Sketcher/feather_sketcher/code.py

@@ -0,0 +1,116 @@
+# SPDX-FileCopyrightText: 2022 Carter Nelson for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+
+#
+# Dual Knob Sketcher
+#
+
+import time
+import board
+import displayio
+import digitalio
+import analogio
+import adafruit_ili9341
+from simpleio import map_range
+
+#--| User Config |---------------------------------------------------
+SKETCH_SCALE      = 3
+DRAW_COLOR        = 0xFFFFFF
+BACKGROUND_COLOR  = 0x000000
+PEN_UP_COLOR      = 0xFF0000
+PEN_DOWN_COLOR    = 0x00FF00
+KNOB_READS        = 10
+KNOB_DELAY        = 0.001
+#--| User Config |---------------------------------------------------
+
+# Feather M4 + 2.4" TFT FeatherWing setup
+DISPLAY_WIDTH = 320
+DISPLAY_HEIGHT = 240
+SKETCH_WIDTH = DISPLAY_WIDTH // SKETCH_SCALE
+SKETCH_HEIGHT = DISPLAY_HEIGHT // SKETCH_SCALE
+PEN_SWITCH = board.D12
+CLEAR_BUTTON = board.D11
+X_KNOB = board.A0
+Y_KNOB = board.A1
+
+# set up knobs
+x_knob = analogio.AnalogIn(X_KNOB)
+y_knob = analogio.AnalogIn(Y_KNOB)
+
+# set up button
+clear_button = digitalio.DigitalInOut(CLEAR_BUTTON)
+clear_button.switch_to_input(pull=digitalio.Pull.UP)
+
+# set up pen up/down switch
+pen_switch = digitalio.DigitalInOut(PEN_SWITCH)
+pen_switch.switch_to_input(pull=digitalio.Pull.UP)
+
+# set up display
+displayio.release_displays()
+
+spi = board.SPI()
+tft_cs = board.D9
+tft_dc = board.D10
+tft_rst = board.D6
+display_bus = displayio.FourWire(
+    spi, command=tft_dc, chip_select=tft_cs, reset=tft_rst
+)
+display = adafruit_ili9341.ILI9341(display_bus, width=DISPLAY_WIDTH, height=DISPLAY_HEIGHT)
+
+# add base UI element
+splash = displayio.Group(scale=SKETCH_SCALE)
+display.show(splash)
+
+# add sketch
+sketch_bitmap = displayio.Bitmap(SKETCH_WIDTH, SKETCH_HEIGHT, 2)
+sketch_palette = displayio.Palette(2)
+sketch_palette[0] = BACKGROUND_COLOR
+sketch_palette[1] = DRAW_COLOR
+sketch = displayio.TileGrid(sketch_bitmap, pixel_shader=sketch_palette, x=0, y=0)
+splash.append(sketch)
+
+# add pen cursor
+pen_bitmap = displayio.Bitmap(3, 3, 2)
+pen_palette = displayio.Palette(2)
+pen_palette[0] = BACKGROUND_COLOR
+pen_palette[1] = PEN_DOWN_COLOR
+CURSOR = (
+    1, 1, 1,
+    1, 0, 1,
+    1, 1, 1,
+)
+for i, value in enumerate(CURSOR):
+    pen_bitmap[i] = value
+pen = displayio.TileGrid(pen_bitmap, pixel_shader=pen_palette)
+splash.append(pen)
+
+# helper to average analog knob readings
+def read_knobs(reads, delay):
+    avg_x = avg_y = 0
+    for _ in range(reads):
+        avg_x += x_knob.value
+        avg_y += y_knob.value
+        time.sleep(delay)
+    avg_x /= reads
+    avg_y /= reads
+    xx = map_range(avg_x, 0, 65535, 0, SKETCH_WIDTH - 1)
+    yy = map_range(avg_y, 0, 65535, 0, SKETCH_HEIGHT - 1)
+    return int(xx), int(yy)
+
+#-------
+# MAIN
+#-------
+while True:
+    while clear_button.value:
+        x, y = read_knobs(KNOB_READS, KNOB_DELAY)
+        pen.x = x - 1
+        pen.y = y - 1
+        if pen_switch.value:
+            # PEN DOWN
+            pen_palette[1] = PEN_DOWN_COLOR
+            sketch_bitmap[x, y] = 1
+        else:
+            # PEN UP
+            pen_palette[1] = PEN_UP_COLOR
+    sketch_bitmap.fill(0)