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1f46e67 Jul 16, 2012
@lrvick @invalid-email-address @scjudd
74 lines (51 sloc) 1.77 KB
#!/usr/bin/python
import RPi.GPIO as GPIO
from time import sleep
class HD44780:
def __init__(self, pin_rs=24, pin_e=23, pins_db=[4, 17, 21, 22]):
self.pin_rs = pin_rs
self.pin_e = pin_e
self.pins_db = pins_db
GPIO.setmode(GPIO.BCM)
GPIO.setup(self.pin_e, GPIO.OUT)
GPIO.setup(self.pin_rs, GPIO.OUT)
for pin in self.pins_db:
GPIO.setup(pin, GPIO.OUT)
self.clear()
def clear(self):
""" Blank / Reset LCD """
self.cmd(0x33) # $33 8-bit mode
self.cmd(0x32) # $32 8-bit mode
self.cmd(0x28) # $28 8-bit mode
self.cmd(0x0C) # $0C 8-bit mode
self.cmd(0x06) # $06 8-bit mode
self.cmd(0x01) # $01 8-bit mode
def cmd(self, bits, char_mode=False):
""" Send command to LCD """
sleep(0.001)
bits=bin(bits)[2:].zfill(8)
GPIO.output(self.pin_rs, char_mode)
for pin in self.pins_db:
GPIO.output(pin, False)
for i in range(4):
if bits[i] == "1":
GPIO.output(self.pins_db[::-1][i], True)
GPIO.output(self.pin_e, True)
GPIO.output(self.pin_e, False)
for pin in self.pins_db:
GPIO.output(pin, False)
for i in range(4,8):
if bits[i] == "1":
GPIO.output(self.pins_db[::-1][i-4], True)
GPIO.output(self.pin_e, True)
GPIO.output(self.pin_e, False)
def message(self, text):
""" Send string to LCD. Newline wraps to second line"""
for char in text:
if char == '\n':
self.cmd(0xC0) # next line
else:
self.cmd(ord(char),True)
if __name__ == '__main__':
lcd = HD44780()
lcd.message("I'm Raspberry Pi\n Take a byte!")