Adafruit 4x14段码显示器使用了 I2C 接口的 HT16K33 控制器，可以方便的用 microbit 的I2C驱动。
- 14-seg beer.JPG (58.99 KiB) 查看 2667 次
HT16K33 控制器的主要命令有：
- 0x21 启动振荡器
- 0x80 清除显示
- 0x81 发送 RAM 数据到显示器
- 0x83 显示器以 2Hz 频率闪烁
- 0xE0 Dim the display
- 0xEF 设置最大亮度
显示字符时，我们需要写数据到HT16K33的 RAM，然后将数据发送到显示器。因为我们总是一次发送四个显示器的数据，在切换HT16K33 RAM的起始地址，如0x0。然后是四个双字节对（每个数字的一对），从左到右。每个数字的第二字节是传统的7位模式（除了中间段分成两部分），第一个字节由构成字母表的额外部分（如对角段）。然后将控制字节81发送给数据以“锁定”到显示。
上面所示的位映射可以表示为两个八位二进制数，其中A是最小有效位，按下面的顺序（第一个位没有使用；您可以将其设为0或1）。字节1和2是反向发送的：
| 字节 2 | 字节 1 |
|---|---|
| 0 DP N M L K J H | G2 G1 F E D C B A |
显示段 G1，对应二进制 00000000,01000000，取反后 -> hex 0x40, 0x0
显示 "0"，对应段 F E D C B A - 二进制是 00000000,00111111，取反 -> hex 0x3F, 0x0
显示 "K", 对应段 N K , G1 F E - 二进制 00100100,01110000，取反 -> hex 0x70,0x24
- led_matrix_segments2.png (19.2 KiB) 查看 2667 次
MicroPython 代码：
代码： 全选
from microbit import i2c, sleep
# address of HT16K33 is 0x70
sleep(1) # allow time for display to settle after power on/reset
# start oscillator
i2c.write(0x70, bytearray([0x21]))
# To display something:
# send (i2c device address,([RAM start addr, four pairs of bytes ]))
# i2c.write( 0x70 ,([0x0 ,digit1,digit2,digit3,digit4]))
# turn on the display
# Clear the display
i2c.write(0x70, bytearray([0x80]))
sleep(1000)
# data for each character
# byte1,byte2
#0 = 0x3f,0x0
#1 = 0x6,0x0
#2 = 0xdb,0x0
#3 = 0xcf,0x0
#4 = 0xe6,0x0
#5 = 0xed,0x0
#6 = 0xfd,0x0
#7 = 0x1,0xc
#8 = 0xff,0x0
#9 = 0xc7,0x8
#. = 0x0,0x40
#+ = 0xc0,0x12
#- = 0xc0,0x0
#/ = 0x0,0xc
#| = 0x0,0x10
#\ = 0x0,0x21
#0x = 0x8d,0xc
#all segments = 0x3f,0x3f
#A 0xF7,0x0
#B 0x8F,0x12
#C 0x39,0x0
#D 0xF,0x12
#E 0xF9,0x0
#F 0xF1,0x0
#G 0xBD,0x0
#H 0xF6,0x0
#I 0x9,0x12
#J 0x1E,0x0
#K 0x70,0x24
#L 0x38,0x0
#M 0x36,0x5
#N 0x36,0x21
#O 0x3F,0x0
#P 0xF3,0x0
#Q 0x3F,0x20
#R 0xF3,0x20
#S 0xED,0x0
#T 0x0,0x12
#U 0x3E,0x0
#V 0x30,0xC
#W 0x36,0x28
#X 0x0,0x2D
#Y 0x0,0x15
#Z 0x9,0xC
#a 0x58,0x10
#b 0x78,0x20
#c 0xD8,0x0
#d 0x8E,0x8
#e 0x58,0x8
#f 0x71,0x0
#g 0x8E,0x4
#h 0x70,0x10
#i 0x0,0x10
#j 0xE,0x0
#k 0x0,0x36
#l 0x30,0x0
#m 0xD4,0x10
#n 0x50,0x10
#o 0xDC,0x0
#p 0x70,0x1
#q 0x86,0x4
#r 0x50,0x0
#s 0x88,0x20
#t 0x78,0x0
#u 0x1C,0x0
#v 0x4,0x20
#w 0x14,0x28
#x 0xC0,0x28
#y 0xC,0x28
#z 0x48,0x8
while True:
# Turn on all segments
i2c.write(0x70,bytearray([0x0,0x3f,0x3f,0x3f,0x3f,0x3f,0x3f,0x3f,0x3f]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep(1000)
# print out the character set four at a time
#0 1 2 3
i2c.write(0x70, bytearray([0x0,0x3f,0x0,0x6,0x0,0xdb,0x0,0xcf,0x0]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#4 5 6 7
i2c.write(0x70, bytearray([0x0,0xe6,0x0,0xed,0x0,0xfd,0x0,0x1,0xc]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#8 9 0x all
i2c.write(0x70, bytearray([0x0,0xff,0x0,0xe7,0x0,0xed,0x12,0x3f,0x3f]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#- / . +
i2c.write(0x70, bytearray([0x0,0x0,0x40,0xc0,0x12,0xc0,0x0,0x0,0xc]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#A B C D
i2c.write(0x70, bytearray([0x0,0xF7,0x0,0x8F,0x12,0x39,0x0,0xF,0x12]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#E F G H
i2c.write(0x70, bytearray([0x0,0xF9,0x0,0xF1,0x0,0xBD,0x0,0xF6,0x0]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#I J K L
i2c.write(0x70, bytearray([0x0,0x9,0x12,0x1E,0x0,0x70,0x24,0x38,0x0]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#M N O P
i2c.write(0x70, bytearray([0x0,0x36,0x5,0x36,0x21,0x3F,0x0,0xF3,0x0]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#Q R S T
i2c.write(0x70, bytearray([0x0,0x3F,0x20,0xF3,0x20,0xED,0x0,0x1,0x12]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#U V W X
i2c.write(0x70, bytearray([0x0,0x3E,0x0,0x30,0xC,0x36,0x28,0x0,0x2D]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#Y Z all all
i2c.write(0x70, bytearray([0x0,0x0,0x15,0x9,0xC,0x3f,0x3f,0x3f,0x3f]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#a b c d
i2c.write(0x70, bytearray([0x0,0x58,0x10,0x78,0x20,0xD8,0x0,0x8E,0x8]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#e f g h
i2c.write(0x70, bytearray([0x0,0x58,0x8,0x71,0x0,0x8E,0x4,0x70,0x10]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#i j k l
i2c.write(0x70, bytearray([0x0,0x0,0x10,0xE,0x0,0x0,0x36,0x30,0x0]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#m n o p
i2c.write(0x70, bytearray([0x0,0xD4,0x10,0x50,0x10,0xDC,0x0,0x70,0x1]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#q r s t
i2c.write(0x70, bytearray([0x0,0x86,0x4,0x50,0x0,0x88,0x20,0x78,0x0]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#u v w x
i2c.write(0x70, bytearray([0x0,0x1C,0x0,0x4,0x20,0x14,0x28,0xC0,0x28]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
#y z
i2c.write(0x70, bytearray([0x0,0xC,0x20,0x48,0x8,0x0,0x0,0x0,0x0]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (1000)
# display a message
# | L | O | V | E
i2c.write(0x70,bytearray([0x00,0x38,0x0,0x3f,0x0,0x30,0xC,0xf9,0x0]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep(1000)
# | B | E | E | R
i2c.write(0x70,bytearray([0x00,0x8F,0x12,0xf9,0x00,0xf9,0x00,0xf3,0x20]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep(1000)
i2c.write(0x70, bytearray([0xE0])) # dim the display (range 0xE0 to 0xEF)
sleep (1000)
i2c.write(0x70, bytearray([0xEF])) # full brightness again
sleep (1000)
i2c.write(0x70, bytearray([0x83])) # blink the display (0x83=2Hz blink, 0x85=1Hz, 0x87=0.5Hz)
sleep (3000)
# Clear the display
i2c.write(0x70, bytearray([0x80]))
sleep(1000)
# make a spinney-round thing!
for iterations in range(20):
i2c.write(0x70, bytearray([0x0,0x0,0x12,0x0,0x12,0x0,0x12,0x0,0x12]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (21)
i2c.write(0x70, bytearray([0x0,0x0,0xc,0x0,0xc,0x0,0xc,0x0,0xc]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (20)
i2c.write(0x70, bytearray([0x0,0xc0,0x0,0xc0,0x0,0xc0,0x0,0xc0,0x0]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (20)
i2c.write(0x70, bytearray([0x0,0x0,0x21,0x0,0x21,0x0,0x21,0x0,0x21]))
i2c.write(0x70, bytearray([0x81])) # display on
sleep (20)
# turn off the display
i2c.write(0x70, bytearray([0x80]))
sleep(1000)