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--- lcd.py [2016/07/25 17:08] – created walkeradmin
+++ lcd.py [2023/03/09 22:35] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
-#!/usr/bin/python
+    #!/usr/bin/python
-#
+    #
-# HD44780 LCD Test Script for
+    # HD44780 LCD Test Script for
-# Raspberry Pi
+    # Raspberry Pi
-#
+    #
-# Author : Matt Hawkins
+    # Author : Matt Hawkins
-# Site   : http://www.raspberrypi-spy.co.uk
+    # Site   : http://www.raspberrypi-spy.co.uk
-#
+    #
-# Date   : 03/08/2012
+    # Date   : 03/08/2012
-#
+    #
-# The wiring for the LCD is as follows:
+    # The wiring for the LCD is as follows:
-# 1 : GND
+    # 1 : GND
-# 2 : 5V
+    # 2 : 5V
-# 3 : Contrast (0-5V)*
+    # 3 : Contrast (0-5V)*
-# 4 : RS (Register Select)
+    # 4 : RS (Register Select)
-# 5 : R/W (Read Write)       - GROUND THIS PIN
+    # 5 : R/W (Read Write)       - GROUND THIS PIN
-# 6 : Enable or Strobe
+    # 6 : Enable or Strobe
-# 7 : Data Bit 0             - NOT USED
+    # 7 : Data Bit 0             - NOT USED
-# 8 : Data Bit 1             - NOT USED
+    # 8 : Data Bit 1             - NOT USED
-# 9 : Data Bit 2             - NOT USED
+    # 9 : Data Bit 2             - NOT USED
-# 10: Data Bit 3             - NOT USED
+    # 10: Data Bit 3             - NOT USED
-# 11: Data Bit 4
+    # 11: Data Bit 4
-# 12: Data Bit 5
+    # 12: Data Bit 5
-# 13: Data Bit 6
+    # 13: Data Bit 6
-# 14: Data Bit 7
+    # 14: Data Bit 7
-# 15: LCD Backlight +5V**
+    # 15: LCD Backlight +5V**
-# 16: LCD Backlight GND
+    # 16: LCD Backlight GND
-#import
+    #import
-import RPi.GPIO as GPIO
+    import RPi.GPIO as GPIO
-import time
+    import time
-# Define GPIO to LCD mapping
+    # Define GPIO to LCD mapping
-LCD_RS = 26
+    LCD_RS = 26
-LCD_E  = 19
+    LCD_E  = 19
-LCD_D4 = 13
+    LCD_D4 = 13
-LCD_D5 = 6
+    LCD_D5 = 6
-LCD_D6 = 5
+    LCD_D6 = 5
-LCD_D7 = 11
+    LCD_D7 = 11
-LED_ON = 15
+    LED_ON = 15
-# Define some device constants
+    # Define some device constants
-LCD_WIDTH = 16    # Maximum characters per line
+    LCD_WIDTH = 16    # Maximum characters per line
-LCD_CHR = True
+    LCD_CHR = True
-LCD_CMD = False
+    LCD_CMD = False
-LCD_LINE_1 = 0x80 # LCD RAM address for the 1st line
+    LCD_LINE_1 = 0x80 # LCD RAM address for the 1st line
-LCD_LINE_2 = 0xC0 # LCD RAM address for the 2nd line
+    LCD_LINE_2 = 0xC0 # LCD RAM address for the 2nd line
-# Timing constants
+    # Timing constants
-E_PULSE = 0.00005
+    E_PULSE = 0.00005
-E_DELAY = 0.00005
+    E_DELAY = 0.00005
-def main():
+    def main():
-  # Main program block
+      # Main program block
-  # Initialise display
+      # Initialise display
-  lcd_init()
+      lcd_init()
-  # Toggle backlight on-off-on
+      # Toggle backlight on-off-on
-  GPIO.output(LED_ON, True)
+      GPIO.output(LED_ON, True)
-  time.sleep(1)
+      time.sleep(1)
-  GPIO.output(LED_ON, False)
+      GPIO.output(LED_ON, False)
-  time.sleep(1)
+      time.sleep(1)
-  GPIO.output(LED_ON, True)
+      GPIO.output(LED_ON, True)
-  time.sleep(1)
+      time.sleep(1)
-  # Send some centred test
+      # Send some centred test
-  lcd_byte(LCD_LINE_1, LCD_CMD)
+      lcd_byte(LCD_LINE_1, LCD_CMD)
-  lcd_string("Rasbperry Pi",2)
+      lcd_string("Rasbperry Pi",2)
-  lcd_byte(LCD_LINE_2, LCD_CMD)
+      lcd_byte(LCD_LINE_2, LCD_CMD)
-  lcd_string("Model B",2)
+      lcd_string("Model B",2)
-  time.sleep(3) # 3 second delay
+      time.sleep(3) # 3 second delay
-  # Send some left justified text
+      # Send some left justified text
-  lcd_byte(LCD_LINE_1, LCD_CMD)
+      lcd_byte(LCD_LINE_1, LCD_CMD)
-  lcd_string("1234567890123456",1)
+      lcd_string("1234567890123456",1)
-  lcd_byte(LCD_LINE_2, LCD_CMD)
+      lcd_byte(LCD_LINE_2, LCD_CMD)
-  lcd_string("abcdefghijklmnop",1)
+      lcd_string("abcdefghijklmnop",1)
-  time.sleep(3) # 3 second delay
+      time.sleep(3) # 3 second delay
-  # Send some right justified text
+      # Send some right justified text
-  lcd_byte(LCD_LINE_1, LCD_CMD)
+      lcd_byte(LCD_LINE_1, LCD_CMD)
-  lcd_string("Raspberrypi-spy",3)
+      lcd_string("Raspberrypi-spy",3)
-  lcd_byte(LCD_LINE_2, LCD_CMD)
+      lcd_byte(LCD_LINE_2, LCD_CMD)
-  lcd_string(".co.uk",3)
+      lcd_string(".co.uk",3)
-  time.sleep(30)
+      time.sleep(30)
-  # Turn off backlight
+      # Turn off backlight
-  GPIO.output(LED_ON, False)
+      GPIO.output(LED_ON, False)
-def lcd_init():
+    def lcd_init():
-  GPIO.setmode(GPIO.BCM)       # Use BCM GPIO numbers
+      GPIO.setmode(GPIO.BCM)       # Use BCM GPIO numbers
-  GPIO.setup(LCD_E, GPIO.OUT)  # E
+      GPIO.setup(LCD_E, GPIO.OUT)  # E
-  GPIO.setup(LCD_RS, GPIO.OUT) # RS
+      GPIO.setup(LCD_RS, GPIO.OUT) # RS
-  GPIO.setup(LCD_D4, GPIO.OUT) # DB4
+      GPIO.setup(LCD_D4, GPIO.OUT) # DB4
-  GPIO.setup(LCD_D5, GPIO.OUT) # DB5
+      GPIO.setup(LCD_D5, GPIO.OUT) # DB5
-  GPIO.setup(LCD_D6, GPIO.OUT) # DB6
+      GPIO.setup(LCD_D6, GPIO.OUT) # DB6
-  GPIO.setup(LCD_D7, GPIO.OUT) # DB7
+      GPIO.setup(LCD_D7, GPIO.OUT) # DB7
-  GPIO.setup(LED_ON, GPIO.OUT) # Backlight enable
+      GPIO.setup(LED_ON, GPIO.OUT) # Backlight enable
-  # Initialise display
+      # Initialise display
-  lcd_byte(0x33,LCD_CMD)
+      lcd_byte(0x33,LCD_CMD)
-  lcd_byte(0x32,LCD_CMD)
+      lcd_byte(0x32,LCD_CMD)
-  lcd_byte(0x28,LCD_CMD)
+      lcd_byte(0x28,LCD_CMD)
-  lcd_byte(0x0C,LCD_CMD)
+      lcd_byte(0x0C,LCD_CMD)
-  lcd_byte(0x06,LCD_CMD)
+      lcd_byte(0x06,LCD_CMD)
-  lcd_byte(0x01,LCD_CMD)
+      lcd_byte(0x01,LCD_CMD)
-def lcd_string(message,style):
+    def lcd_string(message,style):
-  # Send string to display
+      # Send string to display
-  # style=1 Left justified
+      # style=1 Left justified
-  # style=2 Centred
+      # style=2 Centred
-  # style=3 Right justified
+      # style=3 Right justified
-  if style==1:
+      if style==1:
-    message = message.ljust(LCD_WIDTH," ")
+        message = message.ljust(LCD_WIDTH," ")
-  elif style==2:
+      elif style==2:
-    message = message.center(LCD_WIDTH," ")
+        message = message.center(LCD_WIDTH," ")
-  elif style==3:
+      elif style==3:
-    message = message.rjust(LCD_WIDTH," ")
+        message = message.rjust(LCD_WIDTH," ")
-  for i in range(LCD_WIDTH):
+      for i in range(LCD_WIDTH):
-    lcd_byte(ord(message[i]),LCD_CHR)
+        lcd_byte(ord(message[i]),LCD_CHR)
-def lcd_byte(bits, mode):
+    def lcd_byte(bits, mode):
-  # Send byte to data pins
+      # Send byte to data pins
-  # bits = data
+      # bits = data
-  # mode = True  for character
+      # mode = True  for character
-  #        False for command
+      #        False for command
-  GPIO.output(LCD_RS, mode) # RS
+      GPIO.output(LCD_RS, mode) # RS
-  # High bits
+      # High bits
-  GPIO.output(LCD_D4, False)
+      GPIO.output(LCD_D4, False)
-  GPIO.output(LCD_D5, False)
+      GPIO.output(LCD_D5, False)
-  GPIO.output(LCD_D6, False)
+      GPIO.output(LCD_D6, False)
-  GPIO.output(LCD_D7, False)
+      GPIO.output(LCD_D7, False)
-  if bits&0x10==0x10:
+      if bits&0x10==0x10:
-    GPIO.output(LCD_D4, True)
+        GPIO.output(LCD_D4, True)
-  if bits&0x20==0x20:
+      if bits&0x20==0x20:
-    GPIO.output(LCD_D5, True)
+        GPIO.output(LCD_D5, True)
-  if bits&0x40==0x40:
+      if bits&0x40==0x40:
-    GPIO.output(LCD_D6, True)
+        GPIO.output(LCD_D6, True)
-  if bits&0x80==0x80:
+      if bits&0x80==0x80:
-    GPIO.output(LCD_D7, True)
+        GPIO.output(LCD_D7, True)
-  # Toggle 'Enable' pin
+      # Toggle 'Enable' pin
-  time.sleep(E_DELAY)
+      time.sleep(E_DELAY)
-  GPIO.output(LCD_E, True)
+      GPIO.output(LCD_E, True)
-  time.sleep(E_PULSE)
+      time.sleep(E_PULSE)
-  GPIO.output(LCD_E, False)
+      GPIO.output(LCD_E, False)
-  time.sleep(E_DELAY)
+      time.sleep(E_DELAY)
-  # Low bits
+      # Low bits
-  GPIO.output(LCD_D4, False)
+      GPIO.output(LCD_D4, False)
-  GPIO.output(LCD_D5, False)
+      GPIO.output(LCD_D5, False)
-  GPIO.output(LCD_D6, False)
+      GPIO.output(LCD_D6, False)
-  GPIO.output(LCD_D7, False)
+      GPIO.output(LCD_D7, False)
-  if bits&0x01==0x01:
+      if bits&0x01==0x01:
-    GPIO.output(LCD_D4, True)
+        GPIO.output(LCD_D4, True)
-  if bits&0x02==0x02:
+      if bits&0x02==0x02:
-    GPIO.output(LCD_D5, True)
+        GPIO.output(LCD_D5, True)
-  if bits&0x04==0x04:
+      if bits&0x04==0x04:
-    GPIO.output(LCD_D6, True)
+        GPIO.output(LCD_D6, True)
-  if bits&0x08==0x08:
+      if bits&0x08==0x08:
-    GPIO.output(LCD_D7, True)
+        GPIO.output(LCD_D7, True)
-  # Toggle 'Enable' pin
+      # Toggle 'Enable' pin
-  time.sleep(E_DELAY)
+      time.sleep(E_DELAY)
-  GPIO.output(LCD_E, True)
+      GPIO.output(LCD_E, True)
-  time.sleep(E_PULSE)
+      time.sleep(E_PULSE)
-  GPIO.output(LCD_E, False)
+      GPIO.output(LCD_E, False)
-  time.sleep(E_DELAY)
+      time.sleep(E_DELAY)
-if __name__ == '__main__':
+    if __name__ == '__main__':
-  main()
+      main()