#--------------------------------------
# Orange Pi LCD Tester 
#
# From   : lcd_16x2.py ( 16x2 LCD Test Script)
# By     : Matt Hawkins
# Date   : 06/04/2015
# WWW    : http://www.raspberrypi-spy.co.uk/
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
#--------------------------------------

# 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
from pyA20.gpio import gpio
from pyA20.gpio import port
from time import sleep

# Define GPIO to LCD mapping
LCD_RS = port.PA19
LCD_E  = port.PA7
LCD_D4 = port.PA8
LCD_D5 = port.PA9
LCD_D6 = port.PA10
LCD_D7 = port.PA20

# 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

def main():
# Main program block
  
  gpio.init()
  gpio.setcfg(LCD_E, gpio.OUTPUT)  # E
  gpio.setcfg(LCD_RS, gpio.OUTPUT) # RS
  gpio.setcfg(LCD_D4, gpio.OUTPUT) # DB4
  gpio.setcfg(LCD_D5, gpio.OUTPUT) # DB5
  gpio.setcfg(LCD_D6, gpio.OUTPUT) # DB6
  gpio.setcfg(LCD_D7, gpio.OUTPUT) # DB7

  # Initialise display
  lcd_init()

  while True:
    # Send text
    lcd_string("HackerBoxes.com",LCD_LINE_1)
    lcd_string("hack the planet",LCD_LINE_2)

    sleep(2)

    # Send text
    lcd_string("HackerBoxes.com",LCD_LINE_1)
    lcd_string("HACK THE PLANET",LCD_LINE_2)

    sleep(2)

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
  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)

  # 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
  sleep(E_DELAY)
  gpio.output(LCD_E, True)
  sleep(E_PULSE)
  gpio.output(LCD_E, False)
  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__':

  try:
    main()
  except KeyboardInterrupt:
    pass
  finally:
    lcd_byte(0x01, LCD_CMD)
    lcd_string("Goodbye!",LCD_LINE_1)