#!/usr/bin/python
#--------------------------------------
# ___ ___ _ ____
# / _ \/ _ \(_) __/__ __ __
# / , _/ ___/ /\ \/ _ \/ // /
# /_/|_/_/ /_/___/ .__/\_, /
# /_/ /___/
#
# lcd_16x2.py
# 20x4 LCD Test Script with
# backlight control and text justification
#
# Author : Matt Hawkins
# Date : 06/04/2015
#
# https://www.raspberrypi-spy.co.uk/
#
#--------------------------------------
# The wiring for the LCD is as follows:
# 1 : GND
# 2 : 5V
# 3 : Contrast (0-5V)*
# 4 : RS (Register Select)
# 5 : R/W (Read Write) - GROUND THIS PIN
# 6 : Enable or Strobe
# 7 : Data Bit 0 - NOT USED
# 8 : Data Bit 1 - NOT USED
# 9 : Data Bit 2 - NOT USED
# 10: Data Bit 3 - NOT USED
# 11: Data Bit 4
# 12: Data Bit 5
# 13: Data Bit 6
# 14: Data Bit 7
# 15: LCD Backlight +5V**
# 16: LCD Backlight GND
#import
import RPi.GPIO as GPIO
import time
import subprocess
# Define GPIO to LCD mapping
LCD_RS = 7
LCD_E = 8
LCD_D4 = 25
LCD_D5 = 24
LCD_D6 = 23
LCD_D7 = 18
LED_ON = 15
# Define some device constants
LCD_WIDTH = 20 # 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
LCD_LINE_3 = 0x94 # LCD RAM address for the 3rd line
LCD_LINE_4 = 0xD4 # LCD RAM address for the 4th line
# Timing constants
E_PULSE = 0.0005
E_DELAY = 0.0005
def main():
# Main program block
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
GPIO.setup(LED_ON, GPIO.OUT) # Backlight enable
# Initialise display
lcd_init()
# Toggle backlight on-off-on
lcd_backlight(True)
time.sleep(0.5)
lcd_backlight(False)
time.sleep(0.5)
lcd_backlight(True)
time.sleep(0.5)
while True:
output = subprocess.check_output('minidsp', shell=True);
output_str=str(output,'utf-8')
volume=output_str.split('volume: Gain(')
volume2=volume[1].split(')')
source=output_str.split('source: ')
source2=source[1].split(',')
config=output_str.split('preset: ')
config2=config[1].split(',')
dirac=output_str.split('dirac: ')
dirac2=dirac[1].split(' }')
mute=output_str.split('mute: ')
mute2=mute[1].split(',')
config2adj = int(config2[0])+1
config2[0]=str(config2adj)
if dirac2[0]=="false":
dirac2[0]="Off"
else:
dirac2[0]="On"
if mute2[0]=="false":
mute2[0]="Off"
else:
mute2[0]="On"
lcd_string("Volume: " + volume2[0] + " dB",LCD_LINE_1,1)
lcd_string("Source: " + source2[0] ,LCD_LINE_2,1)
lcd_string("Config: " + config2[0],LCD_LINE_3,1)
lcd_string("Dirac: " + dirac2[0] +" Mute: " + str(mute2[0]),LCD_LINE_4,1)
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 = 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,style):
# Send string to display
# style=1 Left justified
# style=2 Centred
# style=3 Right justified
if style==1:
message = message.ljust(LCD_WIDTH," ")
elif style==2:
message = message.center(LCD_WIDTH," ")
elif style==3:
message = message.rjust(LCD_WIDTH," ")
lcd_byte(line, LCD_CMD)
for i in range(LCD_WIDTH):
lcd_byte(ord(message[i]),LCD_CHR)
def lcd_backlight(flag):
# Toggle backlight on-off-on
GPIO.output(LED_ON, flag)
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
pass
finally:
lcd_byte(0x01, LCD_CMD)
lcd_string("miniDSP",LCD_LINE_1,2)
GPIO.cleanup()
