Create sense_show.py example

examples/sense_show.py

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+#!/usr/bin/env python3
+"""
+This module is an example of driving the sense hat with blue dot.
+
+It shows an array of dots on the ui each corresponding to a pixel on the 16x16 array on the sense hat.
+
+Tapping on a dot toggles that pixel, it is very satisfying.
+"""
+
+from sense_hat import SenseHat
+from time import sleep
+from bluedot import BlueDot
+from signal import pause
+
+sense = SenseHat()
+
+# draw an array of dots corresponding to the pixels on the Sense HAT
+bd=BlueDot(cols=8, rows=10)
+for x in range(8):
+    for y in range(8):
+        bd[x,y].color=(50,50,50)
+
+# add in dots for the controls
+for x in range(8):
+    for y in range(8,10):
+        bd[x,y].color=(255,255,255)
+        bd[x,y].visible = False
+
+# set up the brush dot that defines what color will be painted
+
+brush=(0,0,0)
+brush_dot = bd[0,9]
+brush_dot.visible = True
+
+def change_brush(color):
+    global brush
+    print(f"change_brush{color}")
+    brush_dot.color = color
+    brush=color
+    print(f'Brush: {brush}')
+
+# set up the pallet of colours you can change the brush to
+
+pallet = [(248, 248, 248), (248, 0, 248), (248, 0, 0), (248, 248, 0), (0, 248, 0), (0, 248, 248), (0, 0, 248)]
+change_brush(pallet[-1])
+
+def change_brush_pressed(pos):
+    print('change_brush')
+    color_idx = pos.col-1
+    color = pallet[color_idx]
+    change_brush(color)
+
+for idx, color in enumerate(pallet):
+    dot = bd[idx+1, 9]
+    dot.color=color
+    dot.when_pressed = change_brush_pressed
+    dot.visible = True
+    dot.square = True
+
+# handle interactions with the pixels
+
+def pressed(pos):
+    "handler for bd.when_pressed that toggles a pixel"
+
+    print("dot {}.{} pressed".format(pos.col, pos.row))
+
+    if pos.row > 7:
+        return
+
+    pixel = sense.get_pixel(pos.col, pos.row)
+    print(f'Current pixel:{pixel}, toggling brush color: {brush}')
+
+    if tuple(pixel) == brush: # is the pixel set to the brush?
+        print(f'Pixel already set to {brush}, turning off.')
+        sense.set_pixel(pos.col, pos.row, 0,0,0)
+        bd[pos.col, pos.row].color = (50,50,50)
+    else:
+        print(f'Pixel not set to {brush}, setting.')
+        sense.set_pixel(pos.col, pos.row, brush[0], brush[1], brush[2])
+        bd[pos.col, pos.row].color = brush
+
+bd.when_pressed = pressed
+
+# blink blue to signal ready
+
+sense.clear(0,0,255)
+sleep(1)
+sense.clear(0,0,0)
+
+# pause to keep the script running
+
+pause()