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Update lib

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Elis Axelsson 5 years ago
parent
commit
82b708393d
  1. 11
      code/hcsr04.py

11
hcsr04.py → code/hcsr04.py

@ -1,7 +1,7 @@
import machine, time
from machine import Pin
__version__ = '0.1.0'
__version__ = '0.2.0'
__author__ = 'Roberto Sánchez'
__license__ = "Apache License 2.0. https://www.apache.org/licenses/LICENSE-2.0"
@ -18,7 +18,7 @@ class HCSR04:
"""
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.
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
@ -54,11 +54,11 @@ class HCSR04:
"""
pulse_time = self._send_pulse_and_wait()
# To calculate the distance we get the pulse_time and divide it by 2
# 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
# pulse_time // 2 // 2.91 -> pulse_time // 5.82 -> pulse_time * 100 // 582
mm = pulse_time * 100 // 582
return mm
@ -69,9 +69,10 @@ class HCSR04:
"""
pulse_time = self._send_pulse_and_wait()
# To calculate the distance we get the pulse_time and divide it by 2
# 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
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