#!/usr/bin/env python
# File mm5491_demo.py
# http://www.bristolwatch.com/index.htm
# by Lewis Loflin lewis@sullivan-county.com
# http://www.bristolwatch.com/ele2/rpi_MM5451.htm
# access to GPIO must be through root

# for driving common anode displays
# brightness control eliminates need for resistors
# Vcc 4.75 - 13V

# 7-segment common anode display connected bits 1-8
# 8 LEDs bits 9-16 common anodes

# access to GPIO must be through root
import RPi.GPIO as GPIO
import time

CLK =12
dataBit = 7


GPIO.setup(CLK, GPIO.OUT) # P1 
GPIO.setup(dataBit, GPIO.OUT) # P7 


# Setup IO
GPIO.output(dataBit, 0)
GPIO.output(CLK, 0)

def pulseCLK():
    GPIO.output(CLK, 1)
    GPIO.output(CLK, 0)
    return


# LSB out first!
def ssrWriteLSB(value):
    for  x in range(0,8):
        temp = value & 0x01
        if temp == 0x01:
           GPIO.output(dataBit, 1) # data bit HIGH
        else:
           GPIO.output(dataBit, 0) # data bit LOW
        pulseCLK()
        value = value >> 0x01 # shift left
    return 
    
    
# MSB out first!
def ssrWriteMSB(value):
    for  x in range(0,8):
        temp = value & 0x80
        if temp == 0x80:
           GPIO.output(dataBit, 1) # data bit HIGH
        else:
           GPIO.output(dataBit, 0) # data bit LOW
        pulseCLK()
        value = value << 0x01 # shift left
    return 

    
def zeroWrite(num1):
	GPIO.output(dataBit, 0) # data bit HIGH
	for  x in range(0, num1):
		pulseCLK()
	return 

'''
GPIO.output(dataBit, 1) # data bit HIGH
pulseCLK()
ssrWrite(0b11000110)
zeroWrite()
'''

# 7-segment display code array
segCode =[ 0b00111111, 0b00000110, 0b01011011, 0b01001111, 
0b01100110, 0b01101101, 0b01111101, 0b00000111, 0b01111111, 
0b01100111 ]

for myCount in range(0, 256):
		# start bit
		GPIO.output(dataBit, 1)
		pulseCLK()
		# the "+ 0x80" turns on DP
		ssrWriteLSB(segCode[myCount % 10]) # MOD myCount
		ssrWriteMSB(myCount) # 8 LEDs binary count 0-255
		zeroWrite(21) # pad remaining bits with 0s
		time.sleep(.2)



print "Good by!"
exit