#!/usr/bin/python
#--------------------------------------
#    ___  ___  _ ____
#   / _ \/ _ \(_) __/__  __ __
#  / , _/ ___/ /\ \/ _ \/ // /
# /_/|_/_/  /_/___/ .__/\_, /
#                /_/   /___/
#
#  lcd_16x2.py
#  16x2 LCD Test Script 
#
# Author : Matt Hawkins
# Date   : 06/04/2015
#
# http://www.raspberrypi-spy.co.uk/
#
#  Modified and extended for the MotoMast Control
#  By Courtney E. Krehbiel, October 2015
#
#  Ver. 1.02 change in Dec. 2015 to modify rpmzero.py "SmallSleep" delay variable to 3 from 5
#  Ver. 1.10 change on 2/23/2016 to add docking zero function to rpmzero.py and changes to how nCount is handled in MotoMast2.
#
#--------------------------------------

# The wiring for the LCD is as follows:
# 1 : GND
# 2 : 5V
# 3 : Contrast (0-5V)*
# 4 : RS (Register Select)
# 5 : R/W (Read Write)       - GROUND THIS PIN
# 6 : Enable or Strobe
# 7 : Data Bit 0             - NOT USED
# 8 : Data Bit 1             - NOT USED
# 9 : Data Bit 2             - NOT USED
# 10: Data Bit 3             - NOT USED
# 11: Data Bit 4
# 12: Data Bit 5
# 13: Data Bit 6
# 14: Data Bit 7
# 15: LCD Backlight +5V**
# 16: LCD Backlight GND

#import
import RPi.GPIO as GPIO
import time
import json

# Define GPIO to LCD mapping
LCD_RS = 14
LCD_E  = 15
LCD_D4 = 17
LCD_D5 = 18
LCD_D6 = 27
LCD_D7 = 22


# Define some device constants
LCD_WIDTH = 16    # Maximum characters per line
LCD_CHR = True
LCD_CMD = False

LCD_LINE_1 = 0x80 # LCD RAM address for the 1st line
LCD_LINE_2 = 0xC0 # LCD RAM address for the 2nd line

# Timing constants
E_PULSE = 0.0005
E_DELAY = 0.0005

#CEK Global Variables for MotoMast
BtnPin = 23	# pin 16 for pushbutton, GPIO 23  (GPIO 25, pin 22 on blown new board)
SwUpDown = 24	# pin 18 for up/down switch, GPIO 24  (GPIO 16, pin 36 on blown new board)
# BtnPin = 25	# pin 16 for pushbutton, GPIO 23  (GPIO 25, pin 22 on blown new board)
# SwUpDown = 16	# pin 18 for up/down switch, GPIO 24  (GPIO 16, pin 36 on blown new board)
sHeightLabel = "Height Ft: "
sRPM = "RPM: 0.00"
nRPM = 0
Height = 0
HeightFeet = 0
sHeightFeet = ""
StartTime = 0



def setup():
	# Setup program block
  
	GPIO.setwarnings(False)
	GPIO.setmode(GPIO.BCM)       # Use BCM GPIO numbers
	GPIO.setup(LCD_E, GPIO.OUT)  # E
	GPIO.setup(LCD_RS, GPIO.OUT) # RS
	GPIO.setup(LCD_D4, GPIO.OUT) # DB4
	GPIO.setup(LCD_D5, GPIO.OUT) # DB5
	GPIO.setup(LCD_D6, GPIO.OUT) # DB6
	GPIO.setup(LCD_D7, GPIO.OUT) # DB7


	# Initialise display
	lcd_init()
  
	global sRPM
	global StartTime

	GPIO.setup(BtnPin, GPIO.IN, pull_up_down=GPIO.PUD_UP)	#RPM indicator switch
	GPIO.setup(SwUpDown, GPIO.IN, pull_up_down=GPIO.PUD_UP)				# Up/Down indicator switch

	lcd_string('KD6X Moto-Mast', LCD_LINE_1)		# Provide display initialization info
	lcd_string('Firmware v1.10', LCD_LINE_2)
	time.sleep(4)						# 4 second delay	

	displayheight()						# Initial display of data on display
	lcd_string(sRPM, LCD_LINE_2)				# Display RPM: 0.00 from initial string variable
	sRPM = 'RPM: '						# Reset the string for when running to eliminate extra zeros
	StartTime = time.time()					# Set the clock for RPM timing
	


def displayheight():
	global Height
	global HeightFeet
	global sHeightFeet

	with open('ids.json', 'r') as fp:			# Get current position count from disk
		nCount = json.load(fp)
	fp.close()
#	print 'Ncount: ', str(nCount)
	Height = 120 + (nCount * 1.026)	# Mast goes up 1.026 inches per revolution of winch shaft
	HeightFeet = Height / 12
	HeightFeet = round(HeightFeet,2)
	sHeightFeet = str("%.2f" % HeightFeet)		# Convert to feet, round to one decimal point, and then string
	sNewHeightString = ''.join([sHeightLabel, sHeightFeet])
	lcd_string(sNewHeightString, LCD_LINE_1)

def displayrpm():
	global nRPM
	global StartTime
	global RPMStartUp

	NowTime = time.time()
	nRPM = 60 / (NowTime - StartTime)
#	print 'Start:', str(StartTime), 'Now:', str(NowTime), 'RPM:', str(nRPM)
	nRPM = round(nRPM,2)
	sActualRPM = str("%.2f" % nRPM)
	sNewRPMString = ''.join([sRPM, sActualRPM])
	lcd_string(sNewRPMString, LCD_LINE_2)
	StartTime = NowTime		# Setup start time for accurate RPM capture on next revolution.  First one will be pretty close to 0.


def swcount(ev=None):	#This is the routine that runs everytime the winch shaft rotates on revolution

#	print 'Button pressed: ', str(nCount)

	with open('ids.json', 'r') as fp:			# Get current position count from disk
		nCount = json.load(fp)
	fp.close()

	if GPIO.input(SwUpDown) == GPIO.HIGH:
		nCount = nCount + 1					# Increment or decrement the position counter
	else:
		nCount = nCount - 1

	with open('ids.json', 'w') as fp:	# Write current count to disk just in case motor is stopped
		json.dump(nCount, fp)
	fp.close()

	displayheight()							# Do the math and formatting to output the data
	displayrpm()

		
	

# A few more lines from CEK to set the overall loop
	
def loop():
	while True:	
		GPIO.wait_for_edge(BtnPin, GPIO.FALLING, bouncetime=200)	#Triggers swcount function on debounced falling edge of count pulse.
		swcount()

def destroy():
	lcd_byte(0x01, LCD_CMD)				#Clear display
	lcd_string("Goodbye!",LCD_LINE_1)

	GPIO.cleanup()			#Release resources



# End of CEK code
  
  
  
def lcd_init():
  # Initialise display
  lcd_byte(0x33,LCD_CMD) # 110011 Initialise
  lcd_byte(0x32,LCD_CMD) # 110010 Initialise
  lcd_byte(0x06,LCD_CMD) # 000110 Cursor move direction
  lcd_byte(0x0C,LCD_CMD) # 001100 Display On,Cursor Off, Blink Off
  lcd_byte(0x28,LCD_CMD) # 101000 Data length, number of lines, font size
  lcd_byte(0x01,LCD_CMD) # 000001 Clear display
  time.sleep(E_DELAY)

def lcd_byte(bits, mode):
  # Send byte to data pins
  # bits = data
  # mode = True  for character
  #        False for command

  GPIO.output(LCD_RS, mode) # RS

  # High bits
  GPIO.output(LCD_D4, False)
  GPIO.output(LCD_D5, False)
  GPIO.output(LCD_D6, False)
  GPIO.output(LCD_D7, False)
  if bits&0x10==0x10:
    GPIO.output(LCD_D4, True)
  if bits&0x20==0x20:
    GPIO.output(LCD_D5, True)
  if bits&0x40==0x40:
    GPIO.output(LCD_D6, True)
  if bits&0x80==0x80:
    GPIO.output(LCD_D7, True)

  # Toggle 'Enable' pin
  lcd_toggle_enable()

  # Low bits
  GPIO.output(LCD_D4, False)
  GPIO.output(LCD_D5, False)
  GPIO.output(LCD_D6, False)
  GPIO.output(LCD_D7, False)
  if bits&0x01==0x01:
    GPIO.output(LCD_D4, True)
  if bits&0x02==0x02:
    GPIO.output(LCD_D5, True)
  if bits&0x04==0x04:
    GPIO.output(LCD_D6, True)
  if bits&0x08==0x08:
    GPIO.output(LCD_D7, True)

  # Toggle 'Enable' pin
  lcd_toggle_enable()

def lcd_toggle_enable():
  # Toggle enable
  time.sleep(E_DELAY)
  GPIO.output(LCD_E, True)
  time.sleep(E_PULSE)
  GPIO.output(LCD_E, False)
  time.sleep(E_DELAY)

def lcd_string(message,line):
  # Send string to display
  message = message.ljust(LCD_WIDTH," ")
  lcd_byte(line, LCD_CMD)
  for i in range(LCD_WIDTH):
    lcd_byte(ord(message[i]),LCD_CHR)


if __name__ == '__main__':
	setup()
	try:
		loop()
	except KeyboardInterrupt:  #When 'Ctrl-C' is pressed, the child program destroy() will be executed.
		pass
	finally:
		destroy()