Ultrasonic Sensor HC-SR04 - Revision history

Skwhadmin: /* Code for RP2040 (with the library in the main code) */

2024-06-11T14:15:31Z

Code for RP2040 (with the library in the main code)

← Older revision		Revision as of 16:15, 11 June 2024
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	== Code for RP2040 (with the library in the main code) ==		== Code for RP2040 (with the library in the main code) ==

			This is the version for the Arduino Nano Connect RP2040 using GPIO25 as trigger_pin and GPIO15 as echo_pin.

	<syntaxhighlight lang="python" line='line'>		<syntaxhighlight lang="python" line='line'>

Skwhadmin: /* Code for RP2040 (with the library in the main code) */

2024-06-11T14:13:34Z

Code for RP2040 (with the library in the main code)

← Older revision		Revision as of 16:13, 11 June 2024
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	from machine import Pin		from machine import Pin

			#acknowlegement for the library
	__version__ = '0.2.0'		__version__ = '0.2.0'
	__author__ = 'Roberto Sánchez'		__author__ = 'Roberto Sánchez'
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			# contributed at the UBISS2024 Seminar

	from time import sleep		from time import sleep

Skwhadmin: /* Code for RP2040 */

2024-06-11T14:12:31Z

Code for RP2040

← Older revision		Revision as of 16:12, 11 June 2024
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	</syntaxhighlight>		</syntaxhighlight>

	== Code for RP2040 ==		== Code for RP2040 (with the library in the main code) ==

	<syntaxhighlight lang="python" line='line'>		<syntaxhighlight lang="python" line='line'>

185.38.2.4 at 13:28, 11 June 2024

2024-06-11T13:28:45Z

← Older revision		Revision as of 15:28, 11 June 2024
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	</syntaxhighlight>		</syntaxhighlight>

			== Code for RP2040 ==

			<syntaxhighlight lang="python" line='line'>

			import machine, time
			from machine import Pin

			__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=500230):
			"""
			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




			from time import sleep
			sensor = HCSR04(trigger_pin=25, echo_pin=15)
			sleep(1)
			i=0


			while True:
			distance = sensor.distance_cm()
			print(i, ': Distance:', distance, 'cm')
			i=i+1
			sleep(0.5)

			</syntaxhighlight>
	[[Category:Sensor]]		[[Category:Sensor]]

Mayersven at 07:51, 11 June 2024

2024-06-11T07:51:43Z

← Older revision		Revision as of 09:51, 11 June 2024
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	</syntaxhighlight>		</syntaxhighlight>

			[[Category:Sensor]]

Skwhadmin: /* Background */

2020-08-30T21:34:53Z

Background

← Older revision		Revision as of 23:34, 30 August 2020
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	[[File:Hc-03.JPG\|x300px]]		[[File:Hc-03.JPG\|x300px]]

	[[File:Hc04-03.JPG\|x300px]]		[[File:Hc04-03.JPG\|x300px]]

	[[File:Hc-sr04-1.JPG\|x300px]]		[[File:Hc-sr04-1.JPG\|x300px]]

Skwhadmin: /* Background */

2020-08-30T21:34:43Z

Background

← Older revision		Revision as of 23:34, 30 August 2020
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	Connect Trig to Pin5 and Echo to Pin4 of the ESP8266.		Connect Trig to Pin5 and Echo to Pin4 of the ESP8266.

	[[File:Hc-03.JPG]]		[[File:Hc-03.JPG\|x300px]]

	[[File:Hc04-03.JPG]]		[[File:Hc04-03.JPG\|x300px]]

	[[File:Hc-sr04-1.JPG\|x300px]]		[[File:Hc-sr04-1.JPG\|x300px]]
	~~[[File:Ultra1.JPG\|x300px]]~~

	<syntaxhighlight lang="python" line='line'>		<syntaxhighlight lang="python" line='line'>

Skwhadmin at 21:34, 30 August 2020

2020-08-30T21:34:17Z

← Older revision		Revision as of 23:34, 30 August 2020
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	= Related Tutorial Videos =		= Related Tutorial Videos =
	<youtube>PJdDUZWeIDs</youtube>		<youtube>PJdDUZWeIDs</youtube>


			= Background =
			connecting it to the ESP8266 and reading the signal in without a library/module.

			Connect Trig to Pin5 and Echo to Pin4 of the ESP8266.

			[[File:Hc-03.JPG]]

			[[File:Hc04-03.JPG]]

			[[File:Hc-sr04-1.JPG\|x300px]]
			[[File:Ultra1.JPG\|x300px]]

			<syntaxhighlight lang="python" line='line'>
			import machine
			import utime


			while True:
			trig=machine.Pin(5, machine.Pin.OUT)
			trig.off()
			utime.sleep_us(2)
			trig.on()
			utime.sleep_us(10)
			trig.off()
			echo=machine.Pin(4, machine.Pin.IN)
			while echo.value() == 0:
			pass
			t1 = utime.ticks_us()
			while echo.value() == 1:
			pass
			t2 = utime.ticks_us()
			cm = (t2 - t1) / 58.0
			print(cm)
			utime.sleep(2)


			</syntaxhighlight>

Skwhadmin: /* Description */

2020-08-30T21:27:15Z

Description

← Older revision		Revision as of 23:27, 30 August 2020
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	It sends out an ultrasound signal and detects the echo. By measuring the time you can calculate the distance.		It sends out an ultrasound signal and detects the echo. By measuring the time you can calculate the distance.

			[[File:Hc-sr04-1.JPG\|x300px]]
	[[File:Ultra1.JPG\|x300px]]		[[File:Ultra1.JPG\|x300px]]
	~~[[File:Hc-sr04-1.JPG\|x300px]]~~

	more details:		more details:

Skwhadmin: /* Description */

2020-08-30T21:26:58Z

Description

← Older revision		Revision as of 23:26, 30 August 2020
Line 3:		Line 3:
	It sends out an ultrasound signal and detects the echo. By measuring the time you can calculate the distance.		It sends out an ultrasound signal and detects the echo. By measuring the time you can calculate the distance.

	[[File:Ultra1.JPG\|~~300px~~]]		[[File:Ultra1.JPG\|x300px]]
			[[File:Hc-sr04-1.JPG\|x300px]]

	more details:		more details:

← Older revision		Revision as of 23:34, 30 August 2020
Line 51:		Line 51:

	[[File:Hc-03.JPG\|x300px]]		[[File:Hc-03.JPG\|x300px]]

	[[File:Hc04-03.JPG\|x300px]]		[[File:Hc04-03.JPG\|x300px]]

	[[File:Hc-sr04-1.JPG\|x300px]]		[[File:Hc-sr04-1.JPG\|x300px]]