def main():
GPIO_TRIGGER = 66 #P8.7
GPIO_ECHO = 67 #P8.8
PWM_PORT = 6 #P8.13
LPF_A = 0.5
MIN_DIST = 50.0
MAX_DIST = 150.0
DIST_RANGE = MAX_DIST - MIN_DIST
MIN_FREQ = 220
MAX_FREQ = 880
FREQ_RANGE = MAX_FREQ - MIN_FREQ
try:
print("Press Ctrl+C to finish")
meter = Ultrasonic(GPIO_TRIGGER, GPIO_ECHO)
buzz = Buzzer(6)
dist = meter.read()
time.sleep(0.5)
while True:
distRead = meter.read()
if distRead != Ultrasonic.OUT_OF_RANGE:
dist += (distRead - dist) * LPF_A
print("~ {0:.3f} cm".format(dist))
if dist > MIN_DIST and dist < MAX_DIST:
freq = (((dist - MIN_DIST) / DIST_RANGE) *
FREQ_RANGE) + MIN_FREQ
buzz.playNote(freq, 0.5)
else:
time.sleep(0.5)
else:
print("Out of range!")
time.sleep(0.5)
except KeyboardInterrupt:
print("\nCtrl+C pressed.")
finally:
print("Bye!")
meter.cleanup()
buzz.cleanup()
def main():
'''
Makes a LED to blink according to the distance meassured
by an ultrasonic sensor.
Finish when user press a toggle key.
'''
blinker = Blinker(27, MAX_DELAY) #P8.17
ultrasonic = Ultrasonic(66, 69) #P8.7, P8.9
key = Gpio(65, Gpio.IN) #P8.18
try:
print("Ready. Press toggle key to start.")
#Wait for key down event
while key.getValue() == Gpio.LOW:
sleep(0.2)
#Wait for key up event
while key.getValue() == Gpio.HIGH:
sleep(0.2)
print("Started. Press toggle key again to finish.")
blinker.start()
while key.getValue() == Gpio.LOW:
dist = ultrasonic.read()
delay = calculateDelay(dist)
blinker.setDelay(delay)
sleep(0.2)
print("Bye!")
finally:
key.cleanup()
blinker.stop()
blinker.cleanup()
ultrasonic.cleanup()
class DistanceErrorApp(ExperimentApp):
GPIO_TRIGGER = 66 #P8.7
GPIO_ECHO = 67 #P8.8
def __init__(self):
super().__init__("Distance Error")
self.setPollingPeriod(1)
self._meter = Ultrasonic(DistanceErrorApp.GPIO_TRIGGER,
DistanceErrorApp.GPIO_ECHO)
def getValues(self):
distRead = self._meter.read()
if distRead == Ultrasonic.OUT_OF_RANGE:
distRead = 0
return (100, int(distRead))
def cleanup(self):
self._meter.cleanup()
