初学Python，试着将以前在树莓派上用C语言写的程序改成了Python版本的。四位共阴数码管与树莓派的电路连接方式如下：

a ~ p ------------------------------ GPIO0 ~ GPIO7

d1 ~ d4----------------------------- GPIO11 ~ GPIO8

下面是电路连接好之后的照片：

连接好电路之后写程序，程序代码如下：

#!/usr/bin/env python

import RPi.GPIO as GPIO

import time

BIT0 = 3

BIT1 = 5

BIT2 = 24

BIT3 = 26

segCode = [0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f] #0~9

pins = [11,12,13,15,16,18,22,7,3,5,24,26]

bits = [BIT0, BIT1, BIT2, BIT3]

def print_msg():

print 'Program is running...'

print 'Please press Ctrl+C end the program...'

def digitalWriteByte(val):

GPIO.output(11, val & (0x01 << 0))

GPIO.output(12, val & (0x01 << 1))

GPIO.output(13, val & (0x01 << 2))

GPIO.output(15, val & (0x01 << 3))

GPIO.output(16, val & (0x01 << 4))

GPIO.output(18, val & (0x01 << 5))

GPIO.output(22, val & (0x01 << 6))

GPIO.output(7, val & (0x01 << 7))

def display_1():

GPIO.output(BIT0, GPIO.LOW)

for i in range(10):

digitalWriteByte(segCode[i])

time.sleep(0.5)

def display_2():

for bit in bits:

GPIO.output(bit, GPIO.LOW)

for i in range(10):

digitalWriteByte(segCode[i])

time.sleep(0.5)

def display_3(num):

b0 = num % 10

b1 = num % 100 / 10

b2 = num % 1000 / 100

b3 = num / 1000

if num < 10:

GPIO.output(BIT0, GPIO.LOW)

GPIO.output(BIT1, GPIO.HIGH)

GPIO.output(BIT2, GPIO.HIGH)

GPIO.output(BIT3, GPIO.HIGH)

digitalWriteByte(segCode[b0])

elif num >= 10 and num < 100:

GPIO.output(BIT0, GPIO.LOW)

digitalWriteByte(segCode[b0])

time.sleep(0.002)

GPIO.output(BIT0, GPIO.HIGH)

GPIO.output(BIT1, GPIO.LOW)

digitalWriteByte(segCode[b1])

time.sleep(0.002)

GPIO.output(BIT1, GPIO.HIGH)

elif num >= 100 and num < 1000:

GPIO.output(BIT0, GPIO.LOW)

digitalWriteByte(segCode[b0])

time.sleep(0.002)

GPIO.output(BIT0, GPIO.HIGH)

GPIO.output(BIT1, GPIO.LOW)

digitalWriteByte(segCode[b1])

time.sleep(0.002)

GPIO.output(BIT1, GPIO.HIGH)

GPIO.output(BIT2, GPIO.LOW)

digitalWriteByte(segCode[b2])

time.sleep(0.002)

GPIO.output(BIT2, GPIO.HIGH)

elif num >= 1000 and num < 10000:

GPIO.output(BIT0, GPIO.LOW)

digitalWriteByte(segCode[b0])

time.sleep(0.002)

GPIO.output(BIT0, GPIO.HIGH)

GPIO.output(BIT1, GPIO.LOW)

digitalWriteByte(segCode[b1])

time.sleep(0.002)

GPIO.output(BIT1, GPIO.HIGH)

GPIO.output(BIT2, GPIO.LOW)

digitalWriteByte(segCode[b2])

time.sleep(0.002)

GPIO.output(BIT2, GPIO.HIGH)

GPIO.output(BIT3, GPIO.LOW)

digitalWriteByte(segCode[b3])

time.sleep(0.002)

GPIO.output(BIT3, GPIO.HIGH)

else:

print 'Out of range, num should be 0~9999 !'

def setup():

GPIO.setmode(GPIO.BOARD) #Number GPIOs by its physical location

for pin in pins:

GPIO.setup(pin, GPIO.OUT) #set all pins' mode is output

GPIO.output(pin, GPIO.HIGH) #set all pins are high level(3.3V)

def loop():

while True:

print_msg()

display_1()

time.sleep(1)

display_2()

time.sleep(1)

tmp = int(raw_input('Please input a num(0~9999):'))

for i in range(500):

display_3(tmp)

time.sleep(1)

def destroy(): #When program ending, the function is executed.

for pin in pins:

GPIO.output(pin, GPIO.LOW) #set all pins are low level(0V)

GPIO.setup(pin, GPIO.IN) #set all pins' mode is input

if __name__ == '__main__': #Program starting from here

setup()

try:

loop()

except KeyboardInterrupt:

destroy()