Sample – NeoPixel

from ws2812 import WS2812

chain = WS2812(spi_bus=1, led_count=12)
data = [
    (255, 0, 0),  # red
    (0, 255, 0),  # green
    (0, 0, 255),  # blue
    (85, 85, 85),  # white
    (255, 0, 0),  # red
    (0, 255, 0),  # green
    (0, 0, 255),  # blue
    (85, 85, 85),  # white
    (255, 0, 0),  # red
    (0, 255, 0),  # green
    (0, 0, 255),  # blue
    (85, 85, 85),  # white
]
chain.show(data)

• You need to uplpad ws2812.py to the target board by ampy or copy & paste on REPL.

• For EK-RA6M2, connect as followings:

  NeoPixel-PIN	EK-RA6M2-PIN
  DataIn	P101
  GND	GND
  VCC	5V

• For RA4M1 Clicker, connect as followings:

  NeoPixel-PIN	RA4M1 Clicker-PIN
  DataIn	P101
  GND	GND
  VCC	5V

Notes about NeoPixel driver

• The original is https://github.com/JanBednarik/micropython-ws2812
  One SPI clock is assigned to NeoPixel's low pulse, two clocks are assigned to high pulse, one bit is expressed by four clocks, and it is transmitted by DMA so that the waveform is not disturbed by software processing and interrupts.
• In this implementation, DMA is not used, the encoding method is followed, 1 bit is expressed by 4 clocks, and 1 byte data is transferred by 32-bit transfer of SPI.

• Waveform when transmitting 1-byte data of 01010101