from machine import*
from time import*
import machine, time
__version__ = '0.2.0'
__author__ = 'Roberto Sánchez'
__license__ = "Apache License 2.0. https://www.apache.org/licenses/LICENSE-2.0"
class HCSR04:
"""
Driver to use the untrasonic sensor HC-SR04.
The sensor range is between 2cm and 4m.
The timeouts received listening to echo pin are converted to OSError('Out of range')
"""
# echo_timeout_us is based in chip range limit (400cm)
def __init__(self, trigger_pin, echo_pin, echo_timeout_us=500*2*30):
"""
trigger_pin: Output pin to send pulses
echo_pin: Readonly pin to measure the distance. The pin should be protected with 1k resistor
echo_timeout_us: Timeout in microseconds to listen to echo pin.
By default is based in sensor limit range (4m)
"""
self.echo_timeout_us = echo_timeout_us
# Init trigger pin (out)
self.trigger = Pin(trigger_pin, mode=Pin.OUT, pull=None)
self.trigger.value(0)
# Init echo pin (in)
self.echo = Pin(echo_pin, mode=Pin.IN, pull=None)
def _send_pulse_and_wait(self):
"""
Send the pulse to trigger and listen on echo pin.
We use the method `machine.time_pulse_us()` to get the microseconds until the echo is received.
"""
self.trigger.value(0) # Stabilize the sensor
time.sleep_us(5)
self.trigger.value(1)
# Send a 10us pulse.
time.sleep_us(10)
self.trigger.value(0)
try:
pulse_time = machine.time_pulse_us(self.echo, 1, self.echo_timeout_us)
return pulse_time
except OSError as ex:
if ex.args[0] == 110: # 110 = ETIMEDOUT
raise OSError('Out of range')
raise ex
def distance_mm(self):
"""
Get the distance in milimeters without floating point operations.
"""
pulse_time = self._send_pulse_and_wait()
# To calculate the distance we get the pulse_time and divide it by 2
# (the pulse walk the distance twice) and by 29.1 becasue
# the sound speed on air (343.2 m/s), that It's equivalent to
# 0.34320 mm/us that is 1mm each 2.91us
# pulse_time // 2 // 2.91 -> pulse_time // 5.82 -> pulse_time * 100 // 582
mm = pulse_time * 100 // 582
return mm
def distance_cm(self):
"""
Get the distance in centimeters with floating point operations.
It returns a float
"""
pulse_time = self._send_pulse_and_wait()
# To calculate the distance we get the pulse_time and divide it by 2
# (the pulse walk the distance twice) and by 29.1 becasue
# the sound speed on air (343.2 m/s), that It's equivalent to
# 0.034320 cm/us that is 1cm each 29.1us
cms = (pulse_time / 2) / 29.1
return cms
h=HCSR04(trigger_pin=12, echo_pin=13, echo_timeout_us=500*2*30)
h1=HCSR04(trigger_pin=27, echo_pin=14, echo_timeout_us=500*2*30)
r=Pin(21,Pin.OUT)
b=Pin(15,Pin.OUT)
s=PWM(Pin(2,mode=Pin.OUT))
s.freq(50)
rp=Pin(26,Pin.OUT)
vp=Pin(25,Pin.OUT)
rv=Pin(33,Pin.OUT)
jv=Pin(32,Pin.OUT)
vv=Pin(4,Pin.OUT)
while True:
d=h.distance_cm()
d1=h1.distance_cm()
print(d)
if d<=100:
r.on()
b.off()
sleep(0.2)
r.off()
b.on()
sleep(0.2)
s.duty(75)
rv.on()
rp.on()
vp.off()
else:
r.off()
b.off()
s.duty(27)
print(d1)
if d1<=100:
rp.off()
vp.on()
rv.on()
else:
rp.on()
vp.off()
rv.on()
sleep(2)
rv.off()
for i in range(3):
jv.on()
sleep(0.2)
jv.off()
sleep(0.2)
vv.on()
sleep(2)
vv.off()