Skip to content

Instantly share code, notes, and snippets.

@elktros
Created August 31, 2017 08:47
  • Star 3 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
Star You must be signed in to star a gist
Save elktros/32764c8edee0cf15371d87df74a24834 to your computer and use it in GitHub Desktop.
Interfacing 16x2 LCD with Raspberry Pi
#!/usr/bin/env python
import RPi.GPIO as GPIO
from time import sleep
# Define GPIO to LCD mapping
LCD_RS = 7
LCD_E = 8
LCD_D4 = 25
LCD_D5 = 24
LCD_D6 = 23
LCD_D7 = 18
# 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.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()
while True:
# Send some test
lcd_string("Electronics Hub ",LCD_LINE_1)
lcd_string(" Presents ",LCD_LINE_2)
sleep(3) # 3 second delay
# Send some text
lcd_string("Rasbperry Pi",LCD_LINE_1)
lcd_string("16x2 LCD Test",LCD_LINE_2)
sleep(3) # 3 second delay
# Send some text
lcd_string("1234567890*@$#%&",LCD_LINE_1)
lcd_string("abcdefghijklmnop",LCD_LINE_2)
sleep(3)
def lcd_init():
lcd_display(0x28,LCD_CMD) # Selecting 4 - bit mode with two rows
lcd_display(0x0C,LCD_CMD) # Display On,Cursor Off, Blink Off
lcd_display(0x01,LCD_CMD) # Clear display
sleep(E_DELAY)
def lcd_display(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_display(line, LCD_CMD)
for i in range(LCD_WIDTH):
lcd_display(ord(message[i]),LCD_CHR)
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
pass
finally:
lcd_display(0x01, LCD_CMD)
GPIO.cleanup()
@deathm1
Copy link

deathm1 commented Oct 10, 2019

Thank you so much

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment