RpiZero-MicroPythonにGrove-LED-Bar(GPIO)を接続する

2020/2/21

RpiZero-MicroPython Grove-LED-Bar(GPIO) demo

RpiZero-MicroPython Grove-LED-Bar(GPIO) demo

概要

RpiZeroにGroveコネクタ経由でGrove-LED-Bar(GPIO)を接続し、 BareMetal-MicroPythonでLEDを制御する。

参照URL

BareMetalのMicropythonをRaspberryPi_Zeroにインストールしてみる
Grove - LED Bar
Grove - LCD RGB Backlight

関連モジュールのインストール

以下のようにソースを入手しインストールする。

  git clone https://github.com/mcauser/micropython-my9221.git

  cd micropython-my9221/

  # 以下のファイルをRpiZerp-MicroPythonのブートSDにコピーする
  my9221.py


  

デモ・スクリプト

RpiZeroボードにGrove-LED-Barを以下の接続表のように接続し、LEDを制御する。

GPIOの接続表

pin	Fuction	Grove color
p1/p2	3.3V/5V	RED
p38	GP20	YELLOW
p40	GP21	WHITE
p38	GND	BLACK

今回のLED-Barの場合、3.3Vでも5Vでも動作するようだ。

RpiZeroのピン配列は以下を参照のこと：
Quick reference for the Raspberry Pi Zero W MicroPython

micropython-my9221/に含まれるmy9221_test.pyを以下のように変更してブートSDにコピーする

my9221_test.py(修正版)

  from machine import Pin
  from my9221 import MY9221

  # RpiZero-BareMetal
  ledbar = MY9221(Pin(20), Pin(21))

  # ESP8266
  # ledbar = MY9221(Pin(4), Pin(5))

  # PyBoard
  # ledbar = MY9221(Pin('X8'), Pin('X6'))

  # STM32F446RE + Grove-Base Shield
  # ledbar = MY9221(Pin('B4'), Pin('B10')) # Digital I/O slot#5(D5,D6)

  # all LEDS on, full brightness
  ledbar.level(10)

  # four LEDS on, half brightness
  ledbar.level(4, 0x0F)

  # reverse orientation, first LED is green
  ledbar.reverse(True)
  ledbar.level(1)

  # normal orientation, first LED is red
  ledbar.reverse(False)
  ledbar.level(1)

  # switch on specific leds
  ledbar.bits(0b1111100000)
  ledbar.bits(0b0000011111)
  ledbar.bits(1)
  ledbar.bits(3)
  ledbar.bits(7)

  # first and last LED on, very dim
  ledbar.bits(513, 7)

  # alternating LEDs
  ledbar.bits(0b0101010101)
  ledbar.bits(0b1010101010)
  buf = b'\x00\xff\x00\xff\x00\xff\x00\xff\x00\xff'
  ledbar.bytes(buf)

  # fade out LEDs
  buf = bytearray([0,1,3,7,15,31,63,127,255,255])
  ledbar.reverse(True)
  ledbar.bytes(buf)
  ledbar.reverse(False)
  ledbar.bytes(buf)

  # various brightnesses
  buf = [0,0,0,0,0,255,127,63,15,7]
  ledbar.bytes(buf)

  # cycle through LEDS with various brightnesses
  from time import sleep_ms
  buf = [0,1,3,7,15,31,63,127,255,255]
  for i in range(50):
      buf.insert(0,buf.pop())
      ledbar.bytes(buf)
      sleep_ms(100)

  # random LEDs
  import urandom
  for i in range(100):
      ledbar.bits(urandom.getrandbits(10))

  # walk through all possible LED combinations
  for i in range(1024):
      ledbar.bits(i)

  # Use 8bit greyscale mode (default)
  # LED brightness 0x00-0xFF
  ledbar._write16(0x00) # command
  ledbar._write16(0xFF) # led 1
  ledbar._write16(0xFF) # led 2
  ledbar._write16(0x00) # led 3
  ledbar._write16(0x00) # led 4
  ledbar._write16(0x00) # led 5
  ledbar._write16(0xFF) # led 6
  ledbar._write16(0xFF) # led 7
  ledbar._write16(0x00) # led 8
  ledbar._write16(0x00) # led 9
  ledbar._write16(0x00) # led 10
  ledbar._write16(0x00) # unused channel, required
  ledbar._write16(0x00) # unused channel, required
  ledbar._latch()

  # Use 12bit greyscale mode
  # LED brightness 0x000-0xFFF
  ledbar._write16(0x0100) # command
  ledbar._write16(0x0FFF) # led 1
  ledbar._write16(0x0000) # led 2
  ledbar._write16(0x00FF) # led 3
  ledbar._write16(0x0000) # led 4
  ledbar._write16(0x000F) # led 5
  ledbar._write16(0x000F) # led 6
  ledbar._write16(0x0000) # led 7
  ledbar._write16(0x00FF) # led 8
  ledbar._write16(0x0000) # led 9
  ledbar._write16(0x0FFF) # led 10
  ledbar._write16(0x0000) # unused channel, required
  ledbar._write16(0x0000) # unused channel, required
  ledbar._latch()

  # Use 14bit greyscale mode
  # LED brightness 0x000-0x3FFF
  ledbar._write16(0x0200) # command
  ledbar._write16(0x3FFF) # led 1
  ledbar._write16(0x03FF) # led 2
  ledbar._write16(0x0000) # led 3
  ledbar._write16(0x0000) # led 4
  ledbar._write16(0x0000) # led 5
  ledbar._write16(0x003F) # led 6
  ledbar._write16(0x0003) # led 7
  ledbar._write16(0x0000) # led 8
  ledbar._write16(0x0000) # led 9
  ledbar._write16(0x0000) # led 10
  ledbar._write16(0x0000) # unused channel, required
  ledbar._write16(0x0000) # unused channel, required
  ledbar._latch()

  # Use 16bit greyscale mode
  # LED brightness 0x0000-0xFFFF
  ledbar._write16(0x0300) # command
  ledbar._write16(0xFFFF) # led 1
  ledbar._write16(0x0FFF) # led 2
  ledbar._write16(0x00FF) # led 3
  ledbar._write16(0x000F) # led 4
  ledbar._write16(0x0007) # led 5
  ledbar._write16(0x0003) # led 6
  ledbar._write16(0x0001) # led 7
  ledbar._write16(0x0000) # led 8
  ledbar._write16(0x0000) # led 9
  ledbar._write16(0x0000) # led 10
  ledbar._write16(0x0000) # unused channel, required
  ledbar._write16(0x0000) # unused channel, required
  ledbar._latch()

  

実行

RpiZeroボードに上で作ったブートSDを刺して電源を入れる。
(いうまでもないが、USBシリアルとI2C接続が完了している前提)

以下のように起動後
「import my9221_test」を
入力してプログラムを実行する。
(LEDが点滅する)

  mounting SD card...done
  MicroPython 0fb6bf7 on 2020-02-18; Raspberry Pi with ARM1176JZF-S
  Type "help()" for more information.
  >>> import my9221_test
  >>> 

  

以上