from machine import Pin
import time

trig_pin = Pin(15, Pin.OUT) # Broche GP15 de la Pico
echo_pin = Pin(14, Pin.IN)  # Broche GP14 de la Pico

Data_Pin = Pin(5, Pin.OUT)
Clk_Pin = Pin(1, Pin.OUT)
Enable_Pin = Pin(2, Pin.OUT)

def Write_LCD_Nibble(N)
  Enable_Pin = 1;
  # ****** Write RS *********
  Clk_Pin = 0
  Data_Pin = RS
  Clk_Pin = 1
  Clk_Pin = 0
  # ****** End RS Write

  # Shift in 4 bits
  Mask = 8
  for (t=0; t<4; t++)
    Flag = N & Mask
    if(Flag==0) Data_Pin = 0
    else Data_Pin = 1
    Clk_Pin = 1
    Clk_Pin = 0
    Mask = Mask >> 1

    # One more clock because SC and ST clks are tied
    Clk_Pin = 1
    Clk_Pin = 0
    Data_Pin = 0
    Enable_Pin = 0
    Enable_Pin = 1

def Write_LCD_Data(D)
  RS = 1 #It is Data, not command
  Low_Nibble = D & 15
  High_Nibble = D/16
  Write_LCD_Nibble(High_Nibble)
  Write_LCD_Nibble(Low_Nibble)

def Write_LCD_Cmd(C)
  RS = 0 #It is command, not data
  Low_Nibble = C & 15
  High_Nibble = C/16
  Write_LCD_Nibble(High_Nibble)
  Write_LCD_Nibble(Low_Nibble)

def Initialize_LCD()
  Delay_50ms()
  Write_LCD_Cmd(0x20) # Wake-Up Sequence
  Delay_50ms()
  Write_LCD_Cmd(0x20)
  Delay_50ms()
  Write_LCD_Cmd(0x20)
  Delay_50ms()
  Write_LCD_Cmd(0x28) # 4-bits, 2 lines, 5x7 font
  Delay_50ms()
  Write_LCD_Cmd(0x0C) # Display ON, No cursors
  Delay_50ms()
  Write_LCD_Cmd(0x06) # Entry mode- Auto-increment, No Display shifting
  Delay_50ms()
  Write_LCD_Cmd(0x01)
  Delay_50ms()

 
def Position_LCD(x, y)
  temp = 127 + y
  if (x == 2) temp = temp + 64
  Write_LCD_Cmd(temp)
 
def Write_LCD_Text(StrData)
  q = strlen(StrData)
  for (p = 0; p<q; p++)
    <br="">  temp = StrData[p]
    Write_LCD_Data(temp)
 
Message1 = "3-Wire LCD"
Message2 = "using 74HC595"
 
if __name__ == '__main__':
  CMCON0 = 7 #Disable Comparators
  TRISIO = 0b00001000 #All Outputs except GP3
  ANSEL = 0x00 #No analog i/p
  
  Initialize_LCD()
  
  while True:
    Position_LCD(1,4)
    Write_LCD_Text(Message1)
    Position_LCD(2,2)
    Write_LCD_Text(Message2)
    Delay_ms(1500)
    Write_LCD_Cmd(0x01) #Clear LCD
    delay_ms(1000)