Modified the calculate_brightness function to reduce flickering on gu

Author: makosa-irvin

micropython/examples/galactic_unicorn/light_sensor.py

@@ -30,6 +30,9 @@
 MIN_RANGE = 0.1
 MAX_RANGE = 1
 
+# Rate of display change
+TRANSITION_RATE = 1.0 / 32.0
+
 
 # perform linear interpolation to map a range of values to discrete
 def map_range(
@@ -45,9 +48,14 @@ def map_range(
 
 
 # gets the light sensor value from onboard sensor and interpolates it
-# clamps the brightness values
-def calculate_brightness(current_lsv):
-    brightness_val = map_range(current_lsv)
+# clamps the brightness value it outside the ranges specified
+def calculate_brightness(prev_brightness_val):
+    current_lsv = gu.light()
+    current_brightness_val = map_range(current_lsv)
+
+    # uses the previous value to smooth out display changes reducing flickering
+    brightness_diff = current_brightness_val - prev_brightness_val
+    brightness_val = prev_brightness_val + (brightness_diff * TRANSITION_RATE)
     if brightness_val > 1:
         brightness_val = 1
     elif brightness_val < 0.1:
@@ -59,7 +67,7 @@ def calculate_brightness(current_lsv):
 # draws percentage icon
 def draw_percentage(x, y):
     graphics.rectangle(x + 1, y + 1, 2, 2)
-    graphics.line(x, y + 6, x + 6, y)
+    graphics.line(x + 1, y + 5, x + 6, y)
     graphics.rectangle(x + 4, y + 4, 2, 2)
 
 
@@ -69,17 +77,17 @@ def clear():
     graphics.clear()
 
 
-mode = "auto"
+mode = "auto"  # set auto brightness on
 last = time.ticks_ms()
+brightness_value = MIN_RANGE  # set the initial brightness level to the minimum
 while True:
     current = time.ticks_ms()
 
-    # get light sensor value from the sensor
-    ls_value = gu.light()
-    brightness_value = calculate_brightness(ls_value)
+    # set the display brightness
+    brightness_value = calculate_brightness(brightness_value)
     gu.set_brightness(brightness_value)
-    # calculate brightness percentage
-    bp = (brightness_value / MAX_RANGE) * 100
+
+    bp = (brightness_value / MAX_RANGE) * 100  # gets brightness value in percentage relative to the MAX_LS_VALUE set
 
     # deactivate auto brightness by pressing A
     if gu.is_pressed(GalacticUnicorn.SWITCH_A):
@@ -110,10 +118,11 @@ def clear():
         # draw the text
         graphics.set_pen(CURRENT_COLOUR)
         graphics.text("BRT: ", 0, 1, scale=1)
+
         # measure the rest of the text before drawing to right align it
-        text_width = graphics.measure_text(f"{bp:.0f}/°", scale=1)
+        text_width = graphics.measure_text(f"{bp:.0f}  ", scale=1)
         graphics.text(f"{bp:.0f}", WIDTH - text_width, 1, scale=1)
-        draw_percentage((WIDTH - text_width) + 10, 1)
+        draw_percentage((WIDTH - 8), 1)
 
         # draw a bar for the background
         graphics.set_pen(GREY)