Obstacle Avoiding Robot With IR Sensors

Hello, this is my first blog post. Currently I am in 4th semester of Electronic Engineering at Sir Syed University Karachi Pakistan. I wanted to make a robot without microcontroller but I didn't wanted to make an LFR because I already made it as a project of EDC in 3rd semester. So I searched on the internet looked some really cool robots but they included microcontroller programming that I seriously don't wanted to do at this stage. After quite searching I came with the idea of "Obstacle Avoiding Robot". I got the Circuit diagram from http://www.roboticsbible.com here is the photo after completion:

Obstacle Avoiding Robot

Ok LETS MAKE IT...!! 

Step 1: (COMPONENTS)

Gather the components:

For IR SENSORS:

1) 1K Resistor 

2) 10K Resistor

3) IR Receiver LED's

4) IR Transmitter LED's

5) LM358N OP-AMP IC

6) 10K TRIMPOT

7) 8 Pin IC Logic Chip Socket

8) 3 Pin wire connector

For Main Circuit:

9) IC 7407 Hex inverter IC

10) IC L293D Motor Driven IC 

Other Parts:

11) 12V Geared Motor

12) Wheels

13) Sheet for making body

14) Motor holder (Pipe holder)

15) Castor Wheel

16) 2 Pin wire connector

17) Battery

18) Battery holder

19) Switch

20) Jumpers

21) Verroboard

22) Soldering Iron

23) Soldering Wire

Step 2: (MAKING IR SENSOR MODULES)

Ok so we have all the parts in gathered LETS START BUILDING...!!

First we will make IR Sensor here is the CKT Diagram:

CKT Diagram for IR SENSOR MODULE

NOTE: THERE IS A MISTAKE IN THE DIAGRAM THE POTENTIOMETER WILL BE CONNECTED TO PIN 2 AND IR RECEIVER WILL BE CONNECTED TO PIN 3 OF LM358N IC.

I spend hours troubleshooting this diagram since the circuit was not running correctly finally I found the mistake the pin 2 and 3 of LM358N was wrongly connected.

Make two IR Sensors. 

TESTING:

Connect the battery, 9V battery can be used doesn't matter. I won't harm the IC LM358N

now move your hand towards the IR receiver the LED on pin 1 should glow when your hand is near IR Transmitter. The IR Transmitter LED should be a little tilted towards the IR Reciever LED, it should not be parallel. So that the Infrared rays transmitted from the IR Transmitter after hitting to an object should be reflected towards the Receiver and hence the LED on pin 1 glows. Notice I used two IR Transmitter LEDS across the IR Receiver LED just for accuracy.

Step 3: (MAKING MAIN CIRCUIT)

Lets make the Main circuit diagram:

Main Circuit Diagram

After building this main circuit connect it to 2 IR Sensor module circuits as shown in figure. 

Step 4: (MAKING BODY)

I didn't made the body special, just used single sheet of plastic and pasted the circuit's over it, as shown in figure.

Step 5: (ASSEMBLY)

Assemble all the parts, connect the both IR Sensor Modules with the main circuit. and place it on the body of the Robot. Connect the switch. The IR Sensors should be at LEVEL with the tires as shown

You must be wondering the +5V fixed power supply on the left hand side. When I completed the robot I noticed that the robot was even slow on +9V battery (since I was using 12V Geared motors) so I added another +9V battery. So now I had two batteries both +9V one was new and the other was giving I think 8+ Volt. I added both so I got 9+8 above 17 volt. And now the robot was running with speed.

Step 6: (MAKE A TRACK)

If you want you can make the track I used Sheets of paper as shown in pictures:

ROBOT IN ACTION:

HERE IS THE VIDEO:

https://www.facebook.com/video.php?v=473220692820285&l=4380642576510616884