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- import smbus
- import time
- import time
- import RPi.GPIO as GPIO
- from keypad import keypad
- # Define some device parameters
- I2C_ADDR = 0x27 # I2C device address, if any error, change this address to 0x3f
- LCD_WIDTH = 16 # Maximum characters per line
- # Define some device constants
- LCD_CHR = 1 # Mode - Sending data
- LCD_CMD = 0 # Mode - Sending command
- LCD_LINE_1 = 0x80 # LCD RAM address for the 1st line
- LCD_LINE_2 = 0xC0 # LCD RAM address for the 2nd line
- LCD_LINE_3 = 0x94 # LCD RAM address for the 3rd line
- LCD_LINE_4 = 0xD4 # LCD RAM address for the 4th line
- LCD_BACKLIGHT = 0x08 # On
- #LCD_BACKLIGHT = 0x00 # Off
- ENABLE = 0b00000100 # Enable bit
- # Timing constants
- E_PULSE = 0.0005
- E_DELAY = 0.0005
- #Open I2C interface
- #bus = smbus.SMBus(0) # Rev 1 Pi uses 0
- bus = smbus.SMBus(1) # Rev 2 Pi uses 1
- 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
- time.sleep(E_DELAY)
- def lcd_byte(bits, mode):
- # Send byte to data pins
- # bits = the data
- # mode = 1 for data
- # 0 for command
- bits_high = mode | (bits & 0xF0) | LCD_BACKLIGHT
- bits_low = mode | ((bits<<4) & 0xF0) | LCD_BACKLIGHT
- # High bits
- bus.write_byte(I2C_ADDR, bits_high)
- lcd_toggle_enable(bits_high)
- # Low bits
- bus.write_byte(I2C_ADDR, bits_low)
- lcd_toggle_enable(bits_low)
- def lcd_toggle_enable(bits):
- # Toggle enable
- time.sleep(E_DELAY)
- bus.write_byte(I2C_ADDR, (bits | ENABLE))
- time.sleep(E_PULSE)
- bus.write_byte(I2C_ADDR,(bits & ~ENABLE))
- 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__':
- lcd_init()
- kp = keypad(columnCount = 4)
- ###### Wait for command ending with # and print to LCD
- digit=None
- command = []
- while digit !="#":
- digit = None
- while digit == None:
- digit = kp.getKey()
- seq.append(digit)
- lcd_string(''.join(str(e) for e in command),LCD_LINE_1)
- time.sleep(0.4)
- print(command)
- #try:
- # main()
- #except KeyboardInterrupt:
- # pass
- #finally:
- # lcd_byte(0x01, LCD_CMD)
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