本程序相比上一个矩阵键盘电子琴程序增加了一个矩阵键盘，并把三个矩阵键盘的同一行相连，扫描周期缩短到40ms。增加RGB灯带，每个周期刷新一个灯（随机颜色）。
代码如下
#导入Pin模块
from machine import Pin
import time
from machine import PWM
from neopixel import NeoPixel
import random
#扬声器接13脚和GND，矩阵键盘接线如下
# 创建行的对象
row1 = Pin(12, Pin.OUT)
row2 = Pin(14, Pin.OUT)
row3 = Pin(27, Pin.OUT)
row4 = Pin(26, Pin.OUT)
row_list = [row1, row2, row3, row4] # 将创建的行对象放到list里面
# 创建列的对象
col1 = Pin(15, Pin.IN, Pin.PULL_DOWN)
col2 = Pin(2, Pin.IN, Pin.PULL_DOWN)
col3 = Pin(4, Pin.IN, Pin.PULL_DOWN)
col4 = Pin(16, Pin.IN, Pin.PULL_DOWN)
col5 = Pin(17, Pin.IN, Pin.PULL_DOWN)
col6 = Pin(5, Pin.IN, Pin.PULL_DOWN)
col7 = Pin(18, Pin.IN, Pin.PULL_DOWN)
col8 = Pin(19, Pin.IN, Pin.PULL_DOWN)
col9 = Pin(25, Pin.IN, Pin.PULL_DOWN)
col10 = Pin(33, Pin.IN, Pin.PULL_DOWN)
col11 = Pin(32, Pin.IN, Pin.PULL_DOWN)
col12 = Pin(21, Pin.IN, Pin.PULL_DOWN)
col_list = [col1, col2, col3, col4,col5, col6, col7, col8,col9, col10, col11, col12] # 将创建的列对象放到list里面
pin=22
rgb_num=30
rgb_led=NeoPixel(Pin(pin,Pin.OUT),rgb_num)
d=0
#程序入口
while True:
e=10
d+=1
if d==30:
d=0
a=random.randint(0,255)
b=random.randint(0,255)
c=random.randint(0,255)
rgb_led[d]=(a, b, c)
rgb_led.write()
for i, row in enumerate(row_list): # 遍历序号和对应的值 # 目的：只让某一行通电，其他的行都是0
for temp in row_list: # 遍历行对象
temp.value(0) # 给每一个行对象赋值
row.value(1)
time.sleep_ms(10) # 键盘通电后，延迟一小会
for j, col in enumerate(col_list): # 遍历序号和对应的值
if col.value() == 1: # 给每一个列对象赋值
if i==0 and j==0:
e=22
elif i==1 and j==0:
e=23
elif i==2 and j==0:
e=24
elif i==3 and j==0:
e=25
elif i==0 and j==1:
e=26
elif i==1 and j==1:
e=27
elif i==2 and j==1:
e=31
elif i==3 and j==1:
e=32
elif i==0 and j==2:
e=33
elif i==1 and j==2:
e=34
elif i==2 and j==2:
e=35
elif i==3 and j==2:
e=36
elif i==0 and j==3:
e=37
elif i==1 and j==3:
e=41
elif i==2 and j==3:
e=42
elif i==3 and j==3:
e=43
elif i==0 and j==4:
e=44
elif i==1 and j==4:
e=45
elif i==2 and j==4:
e=46
elif i==3 and j==4:
e=47
elif i==0 and j==5:
e=51
elif i==1 and j==5:
e=52
elif i==2 and j==5:
e=53
elif i==3 and j==5:
e=54
elif i==0 and j==6:
e=55
elif i==1 and j==6:
e=56
elif i==2 and j==6:
e=57
elif i==3 and j==6:
e=61
elif i==0 and j==7:
e=62
elif i==1 and j==7:
e=63
elif i==2 and j==7:
e=64
elif i==3 and j==7:
e=65
elif i==0 and j==8:
e=66
elif i==1 and j==8:
e=67
elif i==2 and j==8:
e=71
elif i==3 and j==8:
e=72
elif i==0 and j==9:
e=73
elif i==1 and j==9:
e=74
elif i==2 and j==9:
e=75
elif i==3 and j==9:
e=76
elif i==0 and j==10:
e=77
elif i==1 and j==10:
e=81
elif i==2 and j==10:
e=82
elif i==3 and j==10:
e=83
elif i==0 and j==11:
e=84
elif i==1 and j==11:
e=85
elif i==2 and j==11:
e=86
elif i==3 and j==11:
e=87
a=0
t=0
if e%10==1 :
a=4186
elif e%10==2 :
a=4698
elif e%10==3 :
a=5274
elif e%10==4 :
a=5587
elif e%10==5 :
a=6272
elif e%10==6 :
a=7040
elif e%10==7 :
a=7901
if e//10<9 :
t=e//10
f=9-t
t=2**f
a=round(a/t)
if e<11 :
a=1
beep=PWM(Pin(13),freq=a,duty=512)
