Raspberry Pi

The HC-SR04 Ultrasonic Sensor is a very affordable proximity/distance sensor that has been used mainly for object avoidance in various robotics projects . It essentially gives your Raspberry Pi eyes / spacial awareness and can prevent your robot from crashing or falling off a table. It has also been used in turret applications, water level sensing, and even as a parking sensor. This simple project will use the HC-SR04 sensor with Raspberry Pi and a Processing sketch to provide a neat little interactive display on your computer screen.

Hardware Required

- Raspberry Pi

- ULTRASONIC Sensor

- 330 Ohm Resistor

- 470 Ohm Resistor

Circuit

Code - Blocks

Code - Python

Create new python file Ultrasonic.py and enter following code. To run the code, open the terminal and go to directory where you code is located and enter the command " sudo python Ultrasonic.py " and hit enter.

 
import RPi.GPIO as GPIO 
import time 
GPIO.setmode(GPIO.BCM) 
GPIO.setup(20, GPIO.OUT) 
GPIO.setup(26, GPIO.IN) 
 
while True: 
    GPIO.output(20,False) 
    time.sleep(2) 
    GPIO.output(20,True) 
    time.sleep(0.00001) 
    GPIO.output(20,False) 
    while GPIO.input(26)==0: 
            pulse_start = time.time() 
    while GPIO.input(26)==1: 
            pulse_end = time.time() 
    pulse_duration = pulse_end  - pulse_start 
    distance =pulse_duration * 17150 
    print(str('Distance :') + str(round(distance, 2)))