class MyThermalPrinter:
"""Thermal Printer class with added button and LED"""
# Poll initial button state and time
def __init__(self, *args, **kwargs):
self.button_pin = int(kwargs.pop('button_pin'))
LED_PIN = int(kwargs.pop('led_pin'))
self.hold_time = int(kwargs.pop('hold_time'))
self.available = True
self.tap_time = 0.01 # Debounce time for button taps
self.next_interval = 0.0 # Time of next recurring operation
self.daily_flag = False # Set after daily trigger occurs
GPIO.setup(LED_PIN, GPIO.OUT)
GPIO.setup(self.button_pin, GPIO.IN, pull_up_down=GPIO.PUD_UP)
self.tp = AdafruitThermal(*args, **kwargs)
#self.available = False
# Enable LED and button (w/pull-up on latter)
self.prev_button_state = GPIO.input(self.button_pin)
self.prev_time = time.time()
self.tap_enable = False
self.hold_enable = False
def check_network(self):
# Processor load is heavy at startup; wait a moment to avoid
# stalling during greeting.
if self.available:
time.sleep(0)
# Show IP address (if network is available)
try:
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.connect(('8.8.8.8', 0))
if self.available:
GPIO.output(LED_PIN, GPIO.HIGH)
#self.tp.print_line('My IP address is ' + s.getsockname()[0])
logger.debug('My IP address is ' + s.getsockname()[0])
#self.tp.feed(3)
GPIO.output(LED_PIN, GPIO.LOW)
except:
if self.available:
GPIO.output(LED_PIN, GPIO.HIGH)
self.tp.bold_on()
self.tp.print_line('Network is unreachable.')
logger.debug('Network is unreachable.')
self.tp.bold_off()
self.tp.print('Connect display and keyboard\n' + \
'for network troubleshooting.')
self.tp.feed(3)
GPIO.output(LED_PIN, GPIO.LOW)
exit(0)
def greeting(self):
GPIO.output(LED_PIN, GPIO.HIGH)
# Print greeting image
if self.available:
self.tp.print_image(Image.open('gfx/hello.png'), True)
self.tp.feed(3)
GPIO.output(LED_PIN, GPIO.LOW)
def query_button(self):
# Poll current button state and time
button_state = GPIO.input(self.button_pin)
t = time.time()
# Has button state changed?
if button_state != self.prev_button_state:
if button_state:
GPIO.output(LED_PIN, GPIO.HIGH)
else:
GPIO.output(LED_PIN, GPIO.LOW)
#print('Button changed')
self.prev_button_state = button_state # Yes, save new state/time
self.prev_time = t
else: # Button state unchanged
if (t - self.prev_time) >= self.hold_time: # Button held more than 'holdTime'?
# Yes it has. Is the hold action as-yet untriggered?
if self.hold_enable == True: # Yep!
print('Hold action to be exec')
self.hold() # Perform hold action (usu. shutdown)
self.hold_enable = False # 1 shot...don't repeat hold action
self.tap_enable = False # Don't do tap action on release
elif (t - self.prev_time) >= self.tap_time: # Not holdTime. tapTime elapsed?
#print('tap')
# Yes. Debounced press or release...
if button_state == True: # Button released?
#print('button_state', button_state)
if self.tap_enable == True: # Ignore if prior hold()
self.tap() # Tap triggered (button released)
print('tap action executed')
self.hold_enable = False
else: # Button pressed
self.tap_enable = True # Enable tap and hold actions
self.hold_enable = True
#print('tap_enable', self.tap_enable)
# LED blinks while idle, for a brief interval every 2 seconds.
# Pin 18 is PWM-capable and a "sleep throb" would be nice, but
# the PWM-related library is a hassle for average users to install
# right now. Might return to this later when it's more accessible.
if ((int(t) & 1) == 0) and ((t - int(t)) < 0.05):
GPIO.output(LED_PIN, GPIO.HIGH)
else:
GPIO.output(LED_PIN, GPIO.LOW)
# Once per day (currently set for 6:30am local time, or when script
# is first run, if after 6:30am), run forecast and sudoku scripts.
loc_time = time.localtime()
if loc_time.tm_hour == 6 and loc_time.tm_min == 30:
if self.daily_flag == False:
self.daily()
self.daily_flag = True
else:
self.daily_flag = False # Reset daily trigger
def tap(self):
"""Called when button is briefly tapped. Invokes time/temperature script."""
GPIO.output(LED_PIN, GPIO.HIGH) # LED on while working
subprocess.call(["python", "timetemp.py"])
GPIO.output(LED_PIN, GPIO.LOW)
def hold(self):
"""Called when button is held down. Prints image, invokes shutdown process."""
GPIO.output(LED_PIN, GPIO.HIGH)
self.tp.print_line('Switching off...')
self.tp.feed(3)
for i in range(10):
GPIO.output(LED_PIN, GPIO.HIGH)
time.sleep(0.5)
GPIO.output(LED_PIN, GPIO.LOW)
subprocess.call("sync")
subprocess.call(["shutdown", "-h", "now"])
GPIO.output(LED_PIN, GPIO.LOW)
def interval(self):
"""Called at periodic intervals (30 seconds by default).
Invokes twitter script.
"""
GPIO.output(LED_PIN, GPIO.HIGH)
p = subprocess.Popen(["python", "twitter.py", str(lastId)],
stdout=subprocess.PIPE)
GPIO.output(LED_PIN, GPIO.LOW)
return p.communicate()[0] # Script pipes back lastId, returned to main
def daily(self):
""" Called once per day (6:30am by default).
Invokes weather forecast and sudoku-gfx scripts.
"""
GPIO.output(LED_PIN, GPIO.HIGH)
subprocess.call(["python", "forecast.py"])
subprocess.call(["python", "sudoku-gfx.py"])
GPIO.output(LED_PIN, GPIO.LOW)
# Test character double-height on & off
printer.double_height_on()
printer.print_line("Double Height ON")
printer.double_height_off()
# Set justification (right, center, left) -- accepts 'L', 'C', 'R'
printer.justify('R')
printer.print_line("Right justified")
printer.justify('C')
printer.print_line("Center justified")
printer.justify('L')
printer.print_line("Left justified")
# Test more styles
printer.bold_on()
printer.print_line("Bold text")
printer.bold_off()
printer.underline_on()
printer.print_line("Underlined text")
printer.underline_off()
printer.set_size('L') # Set type size, accepts 'S', 'M', 'L'
printer.print_line("Large")
printer.set_size('M')
printer.print_line("Medium")
printer.set_size('S')
printer.print_line("Small")
printer.justify('C')
