Freenove Ultimate Starter Kit, Руководство пользователя

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Chapter 18 74HC595 & 7-segment display.
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Python Code 18.2.1 StopWatch
This code use four step four pat mode to drive the stepping motor forward and reverse direction.
1.
Use cd command to enter 16.1.1_SteppingMotor directory of Python code.
cd ~/Freenove_Ultimate_Starter_Kit_for_Raspberry_Pi/Code/Python_Code/18.2.1_StopWatch
2. Use python command to execute code "StopWatch.py".
python StopWatch.py
After the program is executed, 4-Digit 7-segment start displaying a four-digit number dynamically, and the
will plus 1 in each successive second.
The following is the program code:
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i m port RPi . GPIO a s GPIO
i m port time
i m port threading
LSBFIRST = 1
MSBFIRST = 2
#define the pins connect to 74HC595
dataPin = 18 #DS Pin of 74HC595(Pin14)
latchPin = 16 #ST_CP Pin of 74HC595(Pin12)
clockPin = 12 #SH_CP Pin of 74HC595(Pin11)
num = ( 0xc0 , 0xf9 , 0xa4 , 0xb0 , 0x99 , 0x92 , 0x82 , 0xf8 , 0x80 , 0x90 )
digitPin = ( 11 , 13 , 15 , 19 ) # Define the pin of 7-segment display common end
counter = 0 # Variable counter, the number will be dislayed by 7-segment display
t = 0 # define the Timer object
d e f setup ( ):
GPIO . setmode ( GPIO . BOARD ) # Number GPIOs by its physical location
GPIO . setup ( dataPin , GPIO . OUT ) # Set pin mode to output
GPIO . setup ( latchPin , GPIO . OUT )
GPIO . setup ( clockPin , GPIO . OUT )
f o r pin i n digitPin :
GPIO . setup ( pin , GPIO . OUT )
d e f shiftOut ( dPin , cPin , order , val ):
f o r i i n range ( 0 , 8 ):
GPIO . output ( cPin , GPIO . LOW );
i f ( order = = LSBFIRST ):
GPIO . output ( dPin ,( 0x01 &( val >> i )== 0x01 ) a n d GPIO . HIGH o r GPIO . LOW )
e l if ( order = = MSBFIRST ):
GPIO . output ( dPin ,( 0x80 &( val << i )== 0x80 ) a n d GPIO . HIGH o r GPIO . LOW )
GPIO . output ( cPin , GPIO . HIGH )
d e f outData ( data ): #function used to output data for 74HC595
GPIO . output ( latchPin , GPIO . LOW )