原理非常简单,控制各个针脚的高低电平来显示数字,这里我用的是共阳的数码管。不过有一个问题,我第一次显示的时候代码输入数字是9.876不过数码管显示9.875,刚开始我以为代码错了,仔细检查了几遍没有问题。然后用putty跑了一下,打印出来的是9875999 。后来又试了几组数字有的正常显示有的最末尾会减一。求助各位大佬到底为什么?
所需原器件
1 TPYBoard v102 一块
2 四位数码管一个
3 杜邦线若干
4 面包板一块(为了接线方便,可不用)
接线图
四位数码管引脚图
开发板与四位数码管针脚对应:
数码管引脚 | a | b | c | d | e | f | g | dp | 1 | 2 | 3 | 4 |
TPYBoard开发板 | X1 | X2 | X3 | X4 | X5 | X6 | X7 | X8 | Y9 | Y10 | Y11 | Y12 |
fritzing接线图
程序源代码:
import pyb
from pyb import Pin
#数码管a~g dp对应的开发板引脚
d_Pins=[Pin(i,Pin.OUT_PP) for i in ['X1','X2','X3','X4','X5','X6','X7','X8']]
#数码管位段1 2 3 4对应的引脚
w_Pins=[Pin(i,Pin.OUT_PP) for i in ['Y9','Y10','Y11','Y12']]
number={
'0':
[0,0,0,0,0,0,1,1],#0
'1':
[1,1,1,1,0,0,1,1],#1
'2':
[0,0,1,0,0,1,0,1],#2
'3':
[0,0,0,0,1,1,0,1],#3
'4':
[1,0,0,1,1,0,0,1],#4
'5':
[0,1,0,0,1,0,0,1],#5
'6':
[0,1,0,0,0,0,0,1],#6
'7':
[0,0,0,1,1,1,1,1],#7
'8':
[0,0,0,0,0,0,0,1],#8
'9':
[0,0,0,0,1,0,0,1],#9
}
def display(num,dp):
global number
count=0
for pin in d_Pins:#显示num的值
pin.value(number[num][count])
count+=1
if dp==1:
d_Pins[7].value(0)
def clear():
for i in w_Pins:
i.value(0)
for i in d_Pins:
i.value(1)
def showData(num):
#分割出数值的百位、千位、个位和小数位的值
d_num=num
location=d_num.find('.')
if location>0:
d_num=d_num.replace('.','')
while len(d_num)<4:
d_num='0'+d_num
for i in range(0,4):
pyb.udelay(2000)
clear()
w_Pins[3-i].value(1)
if i==location-1:
display(d_num[i],1)
else:
display(d_num[i],0)
if location<0:
for i in range(0,4):
pyb.udelay(2000)
clear()
w_Pins[3-i].value(1)
display(d_num[i],0)
while True:
num='9.601'
showData(num)