#**************************************************************************************
#*
#*  Title:            3x3 LED Cube
#*
#*  Description:      Simple LED cube for soldering practice and demonstrate some
#*                    array handling with GPIO pins
#*                       - Pins P1 to P9 are connected to LED Cathode (-)
#*                       - Layers are connected to LED Anode (+)
#*
#*  Author:           Jacob Groves, Coventry Makerspace
#*
#**************************************************************************************

import RPi.GPIO as GPIO 
from time import sleep

# Assign the individual LED pins a variable name . . . 
P1 = 13
P2 = 19
P3 = 26
P4 = 23
P5 = 24
P6 = 25
P7 = 16
P8 = 20
P9 = 21

# Assign the layers to a nice variable . . . 
Top = 17
Middle = 27
Bottom = 22

# LED sequences represented by an array . . . 
aPins = [P1, P2, P3, P4, P5, P6, P7, P8, P9]  
aPinsReversed = [P9, P8, P7, P6, P5, P4, P3, P2, P1]  
aPinsStar = [P1, P2, P3, P6, P9, P8, P7, P4]  
aPinsStar2 = [P9, P8, P7, P4, P1, P2, P3, P6]  
aPinsSpiral = [P1, P2, P3, P6, P9, P8, P7, P4, P5]  
aPinsSpiralReversed = [P5, P4, P7, P8, P9, P6, P3, P2, P1]  

aLayers = [Top, Middle, Bottom]

# Time delay built in between pin output . .  .
delay = 0.15

#**************************************************************************
#* setupColumns - Initialisation of the pins . . . 
#**************************************************************************
def setupColumns():

	# GPIO pin addressing will use the virtual number . . . 
	GPIO.setmode(GPIO.BCM)

	# Initialise the pins so we can output values to them . . . 
	GPIO.setup(aPins, GPIO.OUT)
	GPIO.setup(aLayers, GPIO.OUT)

	GPIO.output(aPins, False)
	GPIO.output(aLayers, True)
	
#**************************************************************************
#* cyclePins - Receive array of pins & light them up one by one . . . 
#**************************************************************************
def cyclePins(pPins):

	for iPin in pPins:
	
		GPIO.output(iPin, True)
		sleep(delay)
		GPIO.output(iPin, False)

#**************************************************************************
#* cyclePinsPair - Receive 2 arrays of pins & light them up in pairs . . . 
#**************************************************************************
def cyclePinsPair(pPins, pPins2):

	for iPin in range(len(pPins)):
	
		GPIO.output(pPins[iPin], True)
		GPIO.output(pPins2[iPin], True)
		sleep(delay)
		GPIO.output(pPins[iPin], False)
		GPIO.output(pPins2[iPin], False)

		
#**************************************************************************
#* Mainline logic . . . 
#**************************************************************************
try:
	print('Press CTRL+C to stop script')
	i = 0
	while(true):

		# Spinning star . . . 
		GPIO.output(aLayers, True)
		GPIO.output(P5, True)
		cyclePinsPair(aPinsStar, aPinsStar2)
		cyclePinsPair(aPinsStar, aPinsStar2)
		GPIO.output(P5, False)

		# Zig-zaggy columns . . .
		GPIO.output(aLayers, True)
		cyclePins(aPins)
		cyclePins(aPinsReversed)
		GPIO.output(aLayers, False)

		# Spiral columns . . .
		GPIO.output(aLayers, True)
		cyclePins(aPinsSpiral)
		cyclePins(aPinsSpiralReversed)
		GPIO.output(aLayers, False)

		# Zig-zaggy layers . . . 
		GPIO.output(Top, True)
		cyclePins(aPins)
		GPIO.output(Top, False)
		GPIO.output(Middle, True)
		cyclePins(aPinsReversed)
		GPIO.output(Middle, False)
		GPIO.output(Bottom, True)
		cyclePins(aPins)
		GPIO.output(Bottom, False)
		sleep(delay)
		
except KeyboardInterrupt:
	GPIO.cleanup()

finally:
	GPIO.cleanup()