Added support for display backlight control

clock.py

@@ -7,6 +7,17 @@ import traceback
 import copy
 import os
 
+def is_arm():
+    if (os.uname()[4][:3] == 'arm') or (os.uname()[4][:7] == 'aarch64'):
+        return True
+    else:
+        return False
+
+if is_arm():
+    # Do not forget to create udev rule:
+    # echo 'SUBSYSTEM=="backlight",RUN+="/bin/chmod 666 /sys/class/backlight/%k/brightness /sys/class/backlight/%k/bl_power"' | sudo tee -a /etc/udev/rules.d/backlight-permissions.rules
+    from rpi_backlight import Backlight
+
 from kivy.config import Config
 #Config.set('graphics', 'width', '800')
 #Config.set('graphics', 'height', '480')
@@ -137,36 +148,6 @@ Builder.load_string('''
                 on_value: root.display_brightness_slider_value(*args)
                 value_track: True
                 value_track_color: [1, 0, 0, 1]
-            Label:
-                text:"Wifi network"
-                halign: "left"
-                valign: "middle"
-                text_size: self.size
-            Label:
-                text:"wifi name"
-                halign: "left"
-                valign: "middle"
-                text_size: self.size
-            Label:
-                text:"Wifi password"
-                halign: "left"
-                valign: "middle"
-                text_size: self.size
-            Label:
-                text:"wifi password"
-                halign: "left"
-                valign: "middle"
-                text_size: self.size
-            Label:
-                text:"Calendar URL"
-                halign: "left"
-                valign: "middle"
-                text_size: self.size
-            Label:
-                text:"calendar url"
-                halign: "left"
-                valign: "middle"
-                text_size: self.size
     FloatLayout
         id: settings_menu_wake_up_sound
         size_hint: None, None
@@ -269,7 +250,6 @@ class MyClockWidget(FloatLayout):
     # - "set_alarm"
     # - "settings_menu"
     # - "settings_menu_wake_up_sound"
-    # - "calendar"
     view = "clock"
 
     # we need a dirty hack to sensure that radio button is always in sync with selected setting
@@ -285,10 +265,12 @@ class MyClockWidget(FloatLayout):
     vlc = vlc.Instance()
     player = vlc.media_player_new()
 
-    if (os.uname()[4][:3] == 'arm') or (os.uname()[4][:7] == 'aarch64'):
-        is_arm = True
+    is_arm = is_arm()
+
+    if is_arm:
+        backlight = Backlight()
     else:
-        is_arm = False
+        backlight = None
 
     def play_sound(self, source):
         alarm_settings = App.get_running_app().alarm_settings
@@ -309,6 +291,15 @@ class MyClockWidget(FloatLayout):
         alarm_settings = App.get_running_app().alarm_settings
         alarm_settings.alarm_playing = False
 
+    def set_backlight(self, x):
+        offset = 3
+        # 20 steps to from 1 to 100 - offset
+        c = (100 - offset)**(1/20)
+
+        y = c**x + offset
+        z = max(1, round(y))
+        self.backlight.brightness = z
+
     def hide_widget(self, widget, hide=True):
         if hasattr(widget, 'saved_attrs'):
             if not hide:
@@ -638,7 +629,8 @@ class MyClockWidget(FloatLayout):
         alarm_settings = App.get_running_app().alarm_settings
 
         alarm_settings.display_brightness = int(args[1])
-        print("Display brightness changed to " + str(alarm_settings.display_brightness))
+        if self.is_arm:
+            self.set_backlight(alarm_settings.display_brightness)
 
     def on_alarm_button_pressed(self):
         alarm_settings = App.get_running_app().alarm_settings