No flickering clock demo added.

demo_no_flick.py

@@ -0,0 +1,50 @@
+from machine import SPI, Pin
+from uc8151 import UC8151
+import math, array, time, random
+
+spi = SPI(0, baudrate=12000000, phase=0, polarity=0, sck=Pin(18), mosi=Pin(19), miso=Pin(16))
+eink = UC8151(spi,cs=17,dc=20,rst=21,busy=26,speed=3,no_flickering=True,inverted=False,debug=True)
+
+# eink.set_handmade_lut()
+
+def draw_clock_hand(fb,x,y,angle,length,fill=False):
+    angle %= 360
+    angle /= 360
+    angle *= 3.14*2
+    bx1 = int(math.sin(angle-(3.1415/2))*5)
+    by1 = -int(math.cos(angle-(3.1415/2))*5)
+    bx2 = int(math.sin(angle+(3.1415/2))*5)
+    by2 = -int(math.cos(angle+(3.1415/2))*5)
+    hx = int(math.sin(angle)*length)
+    hy = -int(math.cos(angle)*length)
+    fb.poly(x,y,array.array('h',[bx1,by1,bx2,by2,hx,hy]),1,fill)
+
+cx = 128//2
+cy = 296//2 + 296//4
+angle = 0
+tick = 0
+while True:
+    eink.fb.fill(0)
+    draw_clock_hand(eink.fb,cx,cy,angle,60,False)
+    draw_clock_hand(eink.fb,cx,cy,angle//3,30,True)
+    eink.fb.fill_rect(0,0,128,148,1)
+    eink.fb.text(f"no_flick:{eink.no_flickering}",0,0,0)
+
+    rect_size = 30
+    x,y = random.randrange(eink.width-rect_size), \
+          random.randrange(eink.height-rect_size)
+    eink.fb.fill_rect(x,y,30,30,1)
+    eink.fb.rect(x,y,30,30,0)
+    x,y = random.randrange(eink.width-rect_size), \
+          random.randrange(eink.height-rect_size)
+    eink.fb.fill_rect(x,y,30,30,0)
+    eink.fb.rect(x,y,30,30,1)
+
+    eink.update(blocking=True)
+    angle += 9
+    tick += 1
+    # Switch between flickering / no flickering mode to show
+    # the difference.
+    if ((tick+1) % 10) == 0:
+        eink.set_speed(eink.speed,no_flickering=not eink.no_flickering)
+    time.sleep(1)