MicroPython&PICO 8位二进制计数器

人类历史上最早的计算机是帕斯卡的加法机，纯机械式的，十进制，有不少视频可以看到，极精妙。最简单的加法机应该用二进制，象周易里的八卦那样，111→110→101→011……分别对应“连连连”、“断连连”、“连断连”、“连连断”……明显是移位再按位或运算。

在STC89C51的流水灯里也是如此。先是给led一个最低位亮灯。经典51是低位亮起的。

led = 0b11111110;

P1= led;

接着把低位0移动7次，同时按位或0b00000001

for (i=0; i<7; i++) {

led = led << 1 | 0b00000001;

P1 = led;

}

这样就把脑子里的计算soft思维过程，放在电子的hardware电路过程里面了。这种软硬之间的切换和对应，实在神奇。

使用MicroPython也能模拟二进制运算，把数字和LED的亮暗对应到一起，如果有按钮，也是可以输入任意数字的。以下示例摘自Raspberry Pi Pico Essentials(Program, Build, and Master Over 50 Projects with MicroPython and the RP2040 Microprocessor)一书。代码中对LED引脚的list化和二进制串位的补齐，值得学习。

from machine import Pinimport utimePORT = [7, 6, 5, 4, 3, 2, 1, 0] # port connectionsDIR = ["0","0","0","0","0","0","0","0"] # port directonsL = [0]*8
def Configure_Port():    for i in range(0, 8):        if DIR[i] == "0":            L[i] = Pin(PORT[i], Pin.OUT)        else:            L[i] = Pin(PORT[i], Pin.IN)    return
def Port_Output(x):    print('dec b:',x)    b = bin(x) # convert into binary    print('bin b:',b)    b = b.replace("0b", "") # remove leading "0b"    diff = 8 - len(b) # find the length    for i in range (0, diff):        b = "0" + b # insert leading os    for i in range (0, 8):        if b[i] == "1":            L[i].value(1)                    else:            L[i].value(0)        print(b[i],end='')    print('\n--------------------')    return## Configure PORT to all outputs#Configure_Port()## Main program loop. Count up in binary every second#cnt = 0while True:    Port_Output(cnt) # send cnt to port    utime.sleep(1) # wait 1 second    cnt = cnt + 5 if cnt < 255 else 0

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