Raspberry Pi-4 Tutorial || Proteus simulation || LCD Interface || Python || Part-3 || Tamil

Interface Python code :

import RPi.GPIO as GPIO
import time

LCD_RS =5
LCD_RW =6
LCD_E = 7
LCD_D4 = 12
LCD_D5 = 13
LCD_D6 = 14
LCD_D7 = 15

LCD_WIDTH = 16
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 = 0.005
E_DELAY = 0.005

def main():
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(LCD_E, GPIO.OUT) # E
GPIO.setup(LCD_RS, GPIO.OUT) # RS
GPIO.setup(LCD_RW, GPIO.OUT) # RW
GPIO.setup(LCD_D4, GPIO.OUT) # D4
GPIO.setup(LCD_D5, GPIO.OUT) # D5
GPIO.setup(LCD_D6, GPIO.OUT) # D6
GPIO.setup(LCD_D7, GPIO.OUT) # 7
GPIO.output(LCD_RW, 0) # RW=0

lcd_init()

while True:

lcd_string(" Hi" ,LCD_LINE_1)
lcd_string(" WELCOME",LCD_LINE_2)

time.sleep(2)

lcd_string(" THIS IS ",LCD_LINE_1)
lcd_string(" EMBEDDED ICON ",LCD_LINE_2)

time.sleep(2)

lcd_string(" RASPBERRY PI-4",LCD_LINE_1)
lcd_string(" LCD TEST",LCD_LINE_2)

time.sleep(2)

lcd_string(" SUBSCRIBE ",LCD_LINE_1)
lcd_string(" TO OUR CHANNEL",LCD_LINE_2)

time.sleep(2)

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

def lcd_byte(bits, mode):

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__':

try:
main()
except KeyboardInterrupt:
pass
finally:
lcd_byte(0x01, LCD_CMD)
lcd_string("MEET YOU AGAIN!",LCD_LINE_1)
GPIO.cleanup()