Keybow 2040: Speed up RGB.

boards/pimoroni/keybow_2040/code.py

@@ -1,5 +1,5 @@
-from is31fl3731_pixelbuf import Keybow2040Leds
 from keybow_2040 import Keybow2040
+from keybow_2040_rgb import Keybow2040Leds
 
 from kmk.extensions.rgb import RGB, AnimationModes
 from kmk.keys import KC

boards/pimoroni/keybow_2040/keybow_2040_rgb.py

@@ -0,0 +1,77 @@
+import board
+import busio
+from micropython import const
+
+from adafruit_bus_device.i2c_device import I2CDevice
+from adafruit_pixelbuf import PixelBuf
+
+_SHUTDOWN_REGISTER = const(0x0A)
+_CONFIG_BANK = const(0x0B)
+_BANK_ADDRESS = const(0xFD)
+
+_ENABLE_OFFSET = const(0x00)
+_COLOR_OFFSET = const(0x24)
+
+
+class Keybow2040Leds(PixelBuf):
+    '''Supports the Pimoroni Keybow 2040 with 4x4 matrix of RGB LEDs'''
+
+    width = 16
+    height = 3
+
+    # Pixel addresses starting from LED 17,
+    # then offset by 1 to fit register addr
+    _pixel_addr = [
+        (0, 104, 72, 88),  # 0, 0
+        (3, 120, 24, 56),  # 1, 0
+        (6, 96, 64, 80),  # 2, 0
+        (9, 112, 16, 48),  # 3, 0
+        (12, 105, 73, 89),  # 0, 1
+        (15, 121, 25, 57),  # 1, 1
+        (18, 97, 65, 81),  # 2, 1
+        (21, 113, 17, 49),  # 3, 1
+        (24, 106, 74, 90),  # 0, 2
+        (27, 122, 9, 58),  # 1, 2
+        (30, 98, 66, 82),  # 2, 2
+        (33, 114, 1, 50),  # 3, 2
+        (36, 107, 75, 91),  # 0, 3
+        (39, 123, 10, 59),  # 1, 3
+        (42, 99, 67, 83),  # 2, 3
+        (45, 115, 2, 51),  # 3, 3
+    ]
+
+    def __init__(self, size: int = 16):  # size kept for backward compatibility
+        self.i2c = busio.I2C(board.SCL, board.SDA, frequency=400_000)
+        self.i2c_device = I2CDevice(self.i2c, 0x74)
+        self.out_buffer = bytearray(124)
+        self._pixels = 16
+        super().__init__(self._pixels, byteorder='RGB')
+
+        # First byte of buffer is our first LED address
+        self.out_buffer[0] = _COLOR_OFFSET + 17
+
+        with self.i2c_device as i2c:
+            i2c.write(bytes([_BANK_ADDRESS, 0]))
+            i2c.write(bytes([_ENABLE_OFFSET] + [0xFF] * 18))  # Enable all LEDs
+            i2c.write(bytes([_COLOR_OFFSET] + [0x00] * 144))  # Init all to 0
+
+            i2c.write(bytes([_BANK_ADDRESS, _CONFIG_BANK]))
+            i2c.write(bytes([0x00] * 14))  # Clear Mode, Frame, ... etc
+            i2c.write(bytes([_SHUTDOWN_REGISTER, 0x01]))  # 0 == shutdown, 1 == normal
+
+            i2c.write(bytes([_BANK_ADDRESS, 0]))
+
+    def _transmit(self, buffer):
+        # Bring buffer into local scope for a tiny perf improvement
+        out = self.out_buffer
+        # Shuffle the 16 pixel PixelBuf buffer into our 144 LED
+        # display native format.
+        for o, r, g, b in self._pixel_addr:
+            out[r] = buffer[o + 0]
+            out[g] = buffer[o + 1]
+            out[b] = buffer[o + 2]
+
+        with self.i2c_device as i2c:
+            # Write our 124 byte buffer
+            # byte 0 is prefilled with the register address
+            i2c.write(out)