User Manual

def hc595_shift(dat): # Shift the data to 74HC595

for bit in range(0, 8):

GPIO.output(SDI, 0x80 & (dat << bit)) # Assign dat data to SDI pins of HC595 by

bits

GPIO.output(SRCLK, GPIO.HIGH) # Every SRCLK adds one, the shift register moves

one bit.

time.sleep(0.001)

GPIO.output(SRCLK, GPIO.LOW)

GPIO.output(RCLK, GPIO.HIGH) # Everytime RCLK adds one, the HC595 updates output.

time.sleep(0.001)

GPIO.output(RCLK, GPIO.LOW)

leds = ['-', '-', '-', '-', '-', '-', '-', '-'] # the array storing the LED state, used

for command line printing.

while True:

# Change LED status from mode

print " mode"

for onoff in mode: # Assign value to variable onoff by mode[] list

hc595_shift(onoff)

leds[mode.index(onoff)] = 1 # Show which led is on

print leds

time.sleep(sleeptime)

leds[mode.index(onoff)] = '-' # Show the led is off

# for loops in later part work similarly, lighting up LED by list.

Input a 2-bit hexadecimal parameter dat via hc595_in(dat) to control 8 LEDs state, and

hc595_out() will output state to 8 LEDs. In While True, the for loop will shift the LED blinking

list to the hc595_in(dat) function, thus we can see the LED light flow ing.

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