Merge pull request #5 from pimoroni/chip-select-and-examples

Added CS pin definitions, switched to FRONT

examples/framerate.py

@@ -43,7 +43,7 @@ Running at: {}MHz
 # Create ST7735 LCD display class.
 disp = ST7735.ST7735(
     port=0,
-    cs=0,
+    cs=ST7735.BG_SPI_CS_FRONT,
     dc=9,
     backlight=18,
     rotation=90,

examples/gif.py

@@ -39,7 +39,7 @@ else:
 # Create TFT LCD display class.
 disp = ST7735.ST7735(
     port=0,
-    cs=0,
+    cs=ST7735.BG_SPI_CS_FRONT,
     dc=9,
     backlight=18,
     spi_speed_hz=4000000

examples/image.py

@@ -39,7 +39,7 @@ image_file = sys.argv[1]
 # Create ST7735 LCD display class.
 disp = ST7735.ST7735(
     port=0,
-    cs=0,
+    cs=ST7735.BG_SPI_CS_FRONT,
     dc=9,
     backlight=18,
     rotation=90,

examples/scrolling-text.py

@@ -0,0 +1,46 @@
+from PIL import Image
+from PIL import ImageDraw
+from PIL import ImageFont
+import time
+
+import ST7735
+
+
+MESSAGE = "Hello World! How are you today?"
+
+# Create ST7735 LCD display class.
+disp = ST7735.ST7735(
+    port=0,
+    cs=ST7735.BG_SPI_CS_FRONT,
+    dc=9,
+    backlight=18,
+    rotation=90,
+    spi_speed_hz=10000000
+)
+
+# Initialize display.
+disp.begin()
+
+WIDTH = disp.width
+HEIGHT = disp.height
+
+
+img = Image.new('RGB', (WIDTH, HEIGHT), color=(0, 0, 0))
+
+draw = ImageDraw.Draw(img)
+
+font = ImageFont.truetype("/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf", 30)
+
+size_x, size_y = draw.textsize(MESSAGE, font)
+
+text_x = 160
+text_y = (80 - size_y) // 2
+
+t_start = time.time()
+
+while True:
+    x = (time.time() - t_start) * 100
+    x %= (size_x + 160)
+    draw.rectangle((0, 0, 160, 80), (0, 0, 0))
+    draw.text((int(text_x - x), text_y), MESSAGE, font=font, fill=(255, 255, 255))
+    disp.display(img)

examples/shapes.py

@@ -35,7 +35,7 @@ breakout into the rear slot.
 # Create ST7735 LCD display class.
 disp = ST7735.ST7735(
     port=0,
-    cs=0,
+    cs=ST7735.BG_SPI_CS_FRONT,
     dc=9,
     backlight=18,
     rotation=90,

library/ST7735/__init__.py

@@ -26,6 +26,9 @@ import spidev
 import RPi.GPIO as GPIO
 
 
+BG_SPI_CS_BACK = 0
+BG_SPI_CS_FRONT = 1
+
 SPI_CLOCK_HZ = 16000000
 
 # Constants for interacting with display registers.