README.rst

Ultrasonic HC-SR04 Sensor Python Library for Raspberry Pi GPIO

This sensor uses sound waves to provide a means to measure the distance between the sensor and an object. It is not the most accurate distance sensor available, but many projects do not need pinpoint accuracy. After a quick look at Banggood website, you can get five HC-SR04 sensors for 5.07 GBP (6.86 USD). And while the sensor is not the most compact, its low price means a robot vehicle can have a full sensor kit fitted very cheaply.

You can find the article here for more details:

Article.

Example Code

Simplest Program for Distance Measuring:

# Import necessary libraries.
from Bluetin_Echo import Echo

# Define GPIO pin constants.
TRIGGER_PIN = 16
ECHO_PIN = 12
# Initialise Sensor with pins, speed of sound.
speed_of_sound = 315
echo = Echo(TRIGGER_PIN, ECHO_PIN, speed_of_sound)
# Measure Distance 5 times, return average.
samples = 5
result = echo.read('cm', samples)
# Print result.
print(result, 'cm')
# Reset GPIO Pins.
echo.stop()

Example for Taking Multiple Distance Measurements:

"""File: echo_loop.py"""
# Import necessary libraries.
from Bluetin_Echo import Echo

# Define GPIO pin constants.
TRIGGER_PIN = 16
ECHO_PIN = 12
# Initialise Sensor with pins, speed of sound.
speed_of_sound = 315
echo = Echo(TRIGGER_PIN, ECHO_PIN, speed_of_sound)
# Measure Distance 5 times, return average.
samples = 5
# Take multiple measurements.
for counter in range(0, 10):
    result = echo.read('cm', samples)
    # Print result.
    print(result, 'cm')

# Reset GPIO Pins.
echo.stop()

Loop Through Multiple Sensors

"""File: echo_multi_sensor.py"""
# Import necessary libraries.
from time import sleep

from Bluetin_Echo import Echo

# Define pin constants
TRIGGER_PIN_1 = 16
ECHO_PIN_1 = 12
TRIGGER_PIN_2 = 26
ECHO_PIN_2 = 19

# Initialise two sensors.
echo = [Echo(TRIGGER_PIN_1, ECHO_PIN_1)
        , Echo(TRIGGER_PIN_2, ECHO_PIN_2)]

def main():
    sleep(0.1)
    for counter in range(1, 6):
        for counter2 in range(0, len(echo)):
            result = echo[counter2].read('cm', 3)
            print('Sensor {} - {} cm'.format(counter2, round(result,2)))

    echo[0].stop()

if __name__ == '__main__':
    main()