2.2.5 IR Obstacle Avoidance Sensor¶

Introduction¶

In this project, we will learn IR obstacle avoidance module, which is a sensor module that can be used to detect obstacles at short distances, with small interference, easy to assemble, easy to use, etc. It can be widely used in robot obstacle avoidance, obstacle avoidance trolley, assembly line counting, etc.

Components Required¶

Schematic Diagram¶

Experimental Procedures¶

Step 1: Build the circuit

Step 2: Change directory.

cd /home/pi/raphael-kit/python

Step 3: Run.

sudo python3 2.2.5_IrObstacle.py

After the code runs, when you put your hand in front of the module’s probe, the output indicator on the module lights up and the “Detected Barrier!” will be repeatedly printed on the screen until the your hand is removed.

Code

Note

You can Modify/Reset/Copy/Run/Stop the code below. But before that, you need to go to source code path like raphael-kit/python. After modifying the code, you can run it directly to see the effect.

#!/usr/bin/env python3
import RPi.GPIO as GPIO
import time

ObstaclePin = 17

def setup():
   GPIO.setmode(GPIO.BCM)       # Numbers GPIOs by physical location
   GPIO.setup(ObstaclePin, GPIO.IN, pull_up_down=GPIO.PUD_UP)

def loop():
   while True:
      if (0 == GPIO.input(ObstaclePin)):
         print ("Detected Barrier!")
                        time.sleep(1)


def destroy():
   GPIO.cleanup()                     # Release resource

if __name__ == '__main__':     # Program start from here
   setup()
   try:
      loop()
   except KeyboardInterrupt:  # When 'Ctrl+C' is pressed, the child program destroy() will be  executed.
      destroy()

Code Explanation

def setup():
GPIO.setmode(GPIO.BCM)       # Numbers GPIOs by physical location
GPIO.setup(ObstaclePin, GPIO.IN, pull_up_down=GPIO.PUD_UP)

Set the GPIO mode to BCM Numbering. Set ObstaclePin to input mode and initial it to High level (3.3v).

def loop():
   while True:
      if (0 == GPIO.input(ObstaclePin)):
         print ("Detected Barrier!")

When ObstaclePin is low level, print “Detected Barrier!”. It means that an obstacle is detected.

Phenomenon Picture¶