1.13. 计算器

1.13.1. 模块介绍

此实验使用Solder_Key_1C模块和EDU-TFT-1.8模块

*实物图：

Solder_Key_1C模块

../_images/key11.jpg

EDU-TFT-1.8模块

../_images/lcd1.jpg

1.13.2. 思路说明

设计简单计算器，即不包括运算优先级与括号，仅能进行加减乘除运算，但是可以连续计算。 设计思路如下： 获得第一个数时，不做处理 获得第两个数后，计算出结果，计算出结果后情况和仅有一个数相同 当有第三个数进入时，和第二个数处理相同（因为进入时内存中只有一个数）

所以本次实验主要分为两部分，获取数据和计算数据

1.13.3. 编程学习

本代码共需要导入如下库：

from pyb import Pin,Timer
import lcd_show
from lcd_show import *
import pyb
from pyb import Pin

完整代码如下：

from pyb import Pin,Timer
import lcd_show
from lcd_show import *
import pyb
from pyb import Pin

#LCD
usrspi = USR_SPI(scl=Pin('X6',Pin.OUT_PP), sda=Pin('X7', Pin.OUT),dc=Pin('X8', Pin.OUT))
disp = DISPLAY(usrspi,cs=Pin('X5', Pin.OUT),res=Pin('X4', Pin.OUT),led_en=Pin('X3', Pin.OUT))
x1 = Pin('X3',Pin.OUT_PP)
R=[Pin('X9',Pin.OUT_PP),Pin('X10',Pin.OUT_PP),Pin('Y3',Pin.OUT_PP),Pin('Y4',Pin.OUT_PP)]
C=[Pin('Y5',Pin.IN,Pin.PULL_UP),Pin('Y6',Pin.IN,Pin.PULL_UP),Pin('Y8',Pin.IN,Pin.PULL_UP),Pin('Y7',Pin.IN,Pin.PULL_UP)]
formu=["0"]
fir=0
sec=0
#将获取的string转化为float
def transfer(number):
  value1=0
  value2=0
  tag=0
  for i in range(len(number)):
    if number[i]==".":#有小数
      tag=1
      for j in range(i):
        value1+=float(number[j])*pow(10,i-1-j)
      for j in range(i+1,len(number)):
        value1+=float(number[j])*pow(10,i-j)
  if tag==1:
    return value1
  for k in range(len(number)):
    value2+=float(number[k])*pow(10,len(number)-1-k)
  return value2


remove=0
disp.clr(disp.WHITE)
key=1
mark=0#加减乘除
place=0#当前字符所在位置
operator=0#运算符位置
while True:#扫描键盘
  for i in range(0,4):
    R[i].low()
    for k in range(0,4):
      if k!=i:
        R[k].high()
    for j in range(0,4):
      if i==0 and j==0 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('7')
        formu+="7"
        place=place+1
      elif i==0 and j==1 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('8')
        formu+="8"
        place=place+1
      elif i==0 and j==2 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('9')
        formu+="9"
        place=place+1
      elif i==0 and j==3 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('/')
        formu+="/"
        place=place+1
      elif i==1 and j==0 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('4')
        formu+="4"
        place=place+1
      elif i==1 and j==1 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('5')
        formu+="5"
        place=place+1
      elif i==1 and j==2 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('6')
        formu+="6"
        place=place+1
      elif i==1 and j==3 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('*')
        formu+="*"
        place=place+1
      elif i==2 and j==0 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('1')
        formu+="1"
        place=place+1
      elif i==2 and j==1 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('2')
        formu+="2"
        place=place+1
      elif i==2 and j==2 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('3')
        formu+="3"
        place=place+1
      elif i==2 and j==3 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('-')
        formu+="-"
        place=place+1
      elif i==3 and j==0 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('0')
        formu+="0"
        place=place+1
      elif i==3 and j==1 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('.')
        formu+="."
        place=place+1
      elif i==3 and j==2 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('=')
        formu+="="
        place=place+1
      elif i==3 and j==3 and C[j].value()==0:
        pyb.delay(10)
        #if C[j].value()==0:
        print('+')
        formu+="+"
        place=place+1
    pyb.delay(50)
  if len(formu)>1:
    if (((formu[0]=="+") or (formu[0]=="-") or (formu[0]=="*") or (formu[0]=="/")) and len(formu)>1):
      formu=formu[1:]
    if (((formu[-1]=="+") or (formu[-1]=="-") or (formu[-1]=="*") or (formu[-1]=="/") or (formu[-1]=="=")) and len(formu)>=1):
      operator=place
      if remove==0:
        formu=formu[1:]
        remove=remove+1
      if key ==1:
        fir=transfer(formu[0:operator-1])#翻译第一个数
        print("fir  is : ",end=" ")
        print(fir)
        disp.putstr(6,5,str(fir),0x0000)
        if formu[operator-1]=="+":
          mark=0
          disp.putstr(4,6,"+",0x0000)
        if formu[operator-1]=="-":
          mark=1
          disp.putstr(4,6,"-",0x0000)
        if formu[operator-1]=="*":
          mark=2
          disp.putstr(4,6,"*",0x0000)
        if formu[operator-1]=="/":
          mark=3
          disp.putstr(4,6,"/",0x0000)
        formu=list(formu[-1])
        key=key+1#找到第一个数
      else :#不是第一个数
        sec=transfer(formu[:-1])
        print("sec  is : ",end=" ")
        print(sec)
        disp.putstr(6,6,str(sec),0x0000)
        if mark==0:
          fir=fir+sec
        if mark ==1:
          fir=fir-sec
        if mark==2:
          fir=fir*sec
        if mark==3:
          fir=fir/sec
        if len(formu)>=1:#继续计算
          #清空现有的数据显示，添加符号
          if formu[-1]=="+":
            disp.putrect(36,54,8*len(str(sec)),8,0xffff)
            disp.putrect(36,45,8*len(str(fir)),8,0xffff)
            disp.putrect(24,54,8,8,0xffff)
            mark=0
            disp.putstr(4,6,"+",0x0000)
          if formu[-1]=="-":
            disp.putrect(36,54,8*len(str(sec)),8,0xffff)
            disp.putrect(36,45,8*len(str(fir)),8,0xffff)
            disp.putrect(24,54,8,8,0xffff)
            mark=1
            disp.putstr(4,6,"-",0x0000)
          if formu[-1]=="*":
            disp.putrect(36,54,8*len(str(sec)),8,0xffff)
            disp.putrect(36,45,8*len(str(fir)),8,0xffff)
            disp.putrect(24,54,8,8,0xffff)
            mark=2
            disp.putstr(4,6,"*",0x0000)
          if formu[-1]=="/":
            disp.putrect(36,54,8*len(str(sec)),8,0xffff)
            disp.putrect(36,45,8*len(str(fir)),8,0xffff)
            disp.putrect(24,54,8,8,0xffff)
            mark=3
            disp.putstr(4,6,"/",0x0000)
          formu=formu[-1]
          #在fir位置显示结果
          disp.putstr(6,5,str(fir),0x0000)
  if (len(formu)>=1 and formu[-1]=="="):
    #print(fir)
    disp.putstr(6,7,str(fir),0x0000)

输入算式：42-6+1.6-2=

效果如下:

../_images/computer.jpg