Feature/setting colors for individual leds on pixel kit 15

.gitignore

@@ -4,3 +4,4 @@ __pycache__
 .DS_Store
 .pytest_cache
 .coverage
+.idea

communitysdk/retailpixelkit.py

@@ -1,6 +1,14 @@
 from .serialdevice import SerialDevice
 from base64 import b64encode
 
+
+COLUMNS = 16
+ROWS = 8
+PIXEL_COUNT = COLUMNS * ROWS
+OFF = '#000000'
+BLANK_SCREEN = [OFF] * PIXEL_COUNT
+
+
 class RetailPixelKitSerial(SerialDevice):
 	def __init__(self, path):
 		super().__init__(path)
@@ -33,18 +41,49 @@ def hex_to_base64(self, hex_colors):
 		return result.decode()
 
 	def stream_frame(self, frame):
-		'''
+		"""
 		Just send to serial, don't wait until `rpc-response`
-		'''
-		if len(frame) != 128:
-			raise Exception('Frame must contain 128 values')
-		encodedFrame = self.hex_to_base64(frame)
+		:param frame:
+		:return: None
+		"""
+		if len(frame) != PIXEL_COUNT:
+			exc = 'Frame must contain {} values'.format(PIXEL_COUNT)
+			raise Exception(exc)
+
+		encoded_frame = self.hex_to_base64(frame)
 		method = 'lightboard:on'
-		params = [{ 'map': encodedFrame }]
+		params = [{'map': encoded_frame}]
 		request_obj = self.get_request_object(method, params)
 		request_str = self.get_request_string(request_obj)
 		self.conn_send(request_str)
 
+	@classmethod
+	def coord_to_index(cls, x, y):
+		"""
+		Convert an x, y coordinate to an index in a frame list
+		:param x:
+		:param y:
+		:return: int
+		"""
+		return (y * COLUMNS + (x - COLUMNS)) - 1
+
+	@classmethod
+	def pixels_to_frame(cls, pixels):
+		"""
+		Create a frame list of hex colors
+		:param pixels: list tuple (x, y, color)
+		:return: list
+		"""
+		frame = BLANK_SCREEN.copy()
+		for x, y, color in pixels:
+			index = cls.coord_to_index(x, y)
+			frame[index] = color
+		return frame
+
+	def stream_pixels(self, pixels):
+		frame = RetailPixelKitSerial.pixels_to_frame(pixels)
+		self.stream_frame(frame)
+
 	def get_battery_status(self):
 		return self.rpc_request('battery-status', [])
 

example_pixel_kit_stream_pixel.py

@@ -0,0 +1,40 @@
+"""
+This example will stream a single color pixel to Pixel Kit.
+"""
+from communitysdk import list_connected_devices
+from communitysdk import RetailPixelKitSerial as PixelKit
+from communitysdk.retailpixelkit import COLUMNS, ROWS
+from random import randint
+from time import sleep
+
+devices = list_connected_devices()
+pk_filter = filter(lambda device: isinstance(device, PixelKit), devices)
+pk = next(pk_filter, None)  # Get first Pixel Kit
+
+
+def get_random_hex() -> str:
+    random_number = randint(0, 16777215)  # number of possible colors
+    hex_number = str(hex(random_number))
+    hex_number = '#{}'.format(hex_number[2:])
+    return hex_number
+
+
+def get_random_pixel() -> tuple:
+    x = randint(1, COLUMNS)
+    y = randint(1, ROWS)
+    color = get_random_hex()
+    return x, y, color
+
+
+if pk is not None:
+    """
+    A pixel is a tuple with an x and y coordinate and a hexadecimal color
+    prefixed with `#`. 
+    We'll create a random color and coordinate to stream to the Pixel Kit.
+    """
+    while True:
+        pixels = [get_random_pixel()]
+        pk.stream_pixels(pixels)
+        sleep(0.1)
+else:
+    print('No Pixel Kit was found :(')

test/test_retailpixelkitserial.py

@@ -174,3 +174,63 @@ def test_connect_to_wifi_wrong(rpk):
 			patch.object(rpk, 'rpc_request'):
 			rpk.connect_to_wifi(ssid, value)
 		assert "`password` must be a string" in str(err.value)
+
+
+def test_coord_to_index():
+	"""
+	Should return the correct index in the pixel array from x and y coordinates
+	"""
+	assert PixelKit.coord_to_index(1, 1) == 0
+	assert PixelKit.coord_to_index(16, 8) == 127
+
+
+@pytest.fixture
+def pixel1() -> tuple:
+	return 1, 1, '#ffffff'
+
+
+@pytest.fixture
+def pixel2() -> tuple:
+	return 16, 8, '#2b2b2b'
+
+
+class TestPixelsToFrame:
+	from communitysdk.retailpixelkit import BLANK_SCREEN
+
+	def test_empty_list(self):
+		"""
+		Should return a blank screen list when the pixels argument is an empty list
+		"""
+		assert PixelKit.pixels_to_frame([]) == self.BLANK_SCREEN
+
+	def test_pixels_to_frame(self, pixel1, pixel2):
+		"""
+		Should return a list with the pixels at the correct indices
+		"""
+		expected_frame = self.BLANK_SCREEN.copy()
+		color1 = pixel1[2]
+		color2 = pixel2[2]
+		expected_frame[0] = color1
+		expected_frame[127] = color2
+		assert PixelKit.pixels_to_frame([pixel1, pixel2]) == expected_frame
+
+
+class TestStreamPixels:
+	@pytest.fixture
+	def pixels(self, pixel1, pixel2) -> list:
+		return [pixel1, pixel2]
+
+	@pytest.fixture
+	def frame(self, pixels) -> list:
+		return PixelKit.pixels_to_frame(pixels)
+
+	def test_calls_pixels_to_frame(self, rpk, pixels, frame):
+		with patch.object(PixelKit, 'pixels_to_frame', return_value=frame) as pixels_to_frame, \
+				patch.object(rpk, 'stream_frame'):
+			rpk.stream_pixels(pixels)
+			pixels_to_frame.assert_called_with(pixels)
+
+	def test_calls_stream_frame(self, rpk, pixels, frame):
+		with patch.object(rpk, 'stream_frame') as stream_frame:
+			rpk.stream_pixels(pixels)
+			stream_frame.assert_called_with(frame)