Connect HC-SR01 to Raspberry

[Ivan219]

Good day, I connected to the raspberry pi ultrasonic rangefinder HC-SR01 - the instructionshttp://www.modmypi.com/blog/hc-sr04-ult ... spberry-pi. But the program in python gives random values. In what may be the problem?

[joan]

Random values? How random?

You would expect some variation but are you saying the values don't make any sense at all?

[Ivan219]

In the first was more than 4 000 000 cm. And now i have problem:

[Ivan219]

I change code to:

Code: Select all

import time
import RPi.GPIO as GPIO
 
GPIO.setmode(GPIO.BCM)

# Define GPIO to use on Pi
GPIO_TRIGGER = 23
GPIO_ECHO = 24
GPIO.setup(GPIO_TRIGGER,GPIO.OUT)  # Trigger
GPIO.setup(GPIO_ECHO,GPIO.IN)      # Echo
# Set trigger to False (Low)
GPIO.output(GPIO_TRIGGER, False)
time.sleep(0.5)
 
# Send 10us pulse to trigger
GPIO.output(GPIO_TRIGGER, True)
time.sleep(0.00001)
GPIO.output(GPIO_TRIGGER, False)
start = time.time()
while GPIO.input(GPIO_ECHO)==0:
  start = time.time()
 
while GPIO.input(GPIO_ECHO)==1:
  stop = time.time()
# Calculate pulse length
elapsed = stop-start
# Distance pulse travelled in that time is time
# multiplied by the speed of sound (cm/s/2)
dist = elapsed * 1715
print "Distance : %.1f" % dist
# Reset GPIO settings
GPIO.cleanup()
time.sleep(2)

But I have spread to 100 centimeters.

[joan]

The two most likely errors are GPIO numbering or the wiring.

Make sure you are using the same pins as the software thinks you are using.

Because all the wires are the same colour it's a bit hard to make out which wire is going where.

I'd follow each wire back from the sensor to the Pi and not the terminating pin. Check that the pin matches with what the software expects.

[Ivan219]

Yes, problem was in pins, i connected ground, but need to gpio 24. Thank you.