Reworked homescreen (no blinking, only diming)

Added ui.alert()

src/apps/homescreen/layout_homescreen.py

@@ -1,7 +1,6 @@
 from trezor import ui, loop, res
 from trezor.utils import unimport
 
-
 async def swipe_to_rotate():
     from trezor.ui.swipe import Swipe
 
@@ -10,14 +9,32 @@ async def swipe_to_rotate():
         ui.display.orientation(degrees)
 
 
+'''
 async def animate_logo():
     image = res.load('apps/homescreen/res/trezor.toig')
 
     def render(fg):
         ui.display.icon(0, 0, image, fg, ui.BLACK)
-    await ui.animate_pulse(render, ui.WHITE, ui.DARK_GREY, speed=400000)
+    await ui.animate_pulse(render, ui.WHITE, ui.DARK_GREY, speed=800000)
+'''
+
+async def dim_screen():
+    current = ui.display.backlight()
+
+    await loop.Sleep(5*1000000)
+    await ui.backlight_slide(ui.BACKLIGHT_DIM)
 
+    try:
+        while True:
+            await loop.Sleep(1000000)
+    except:
+        # Return back to original brightness
+        ui.display.backlight(current)
 
 @unimport
 async def layout_homescreen():
-    await loop.Wait([swipe_to_rotate(), animate_logo()])
+    image = res.load('apps/homescreen/res/trezor.toig')
+    ui.display.icon(0, 0, image, ui.WHITE, ui.BLACK)
+
+    ui.display.backlight(ui.BACKLIGHT_NORMAL)
+    await loop.Wait([swipe_to_rotate(), dim_screen()])

src/trezor/ui/__init__.py

@@ -45,6 +45,10 @@ MONO   = Display.FONT_MONO
 NORMAL = Display.FONT_NORMAL
 BOLD   = Display.FONT_BOLD
 
+BACKLIGHT_NORMAL = const(127)
+BACKLIGHT_DIM = const(70)
+BACKLIGHT_MAX = const(255)
+
 # icons
 ICON_RESET    = 'trezor/res/reset.toig'
 ICON_WIPE     = 'trezor/res/wipe.toig'
@@ -66,6 +70,25 @@ def blend(ca: int, cb: int, t: float) -> int:
                     lerpi((ca << 3) & 0xF8, (cb << 3) & 0xF8, t))
 
 
+def alert(count=3):
+    current = display.backlight()
+    for i in range(count*2):
+        if i % 2 == 0:
+            display.backlight(BACKLIGHT_MAX)
+            yield loop.Sleep(20000)
+        else:
+            display.backlight(BACKLIGHT_NORMAL)
+            yield loop.Sleep(80000)
+
+    display.backlight(current)
+
+def backlight_slide(val, speed=20000):
+    current = display.backlight()
+
+    for i in range(current, val, -1 if current > val else 1):
+        display.backlight(i)
+        await loop.Sleep(speed)
+
 def animate_pulse(func, ca, cb, speed=200000, delay=30000):
     while True:
         # normalize sin from interval -1:1 to 0:1