Arduino Robotics Workshop

Day 2Sudar Muthu (@sudarmuthu)

http://hardwarefun.com/arduino-workshophttp://github.com/sudar

2

Basics of Robotics Using Breadboard Digital and Analog I/P and O/P Serial Communication Controlling DC Motors Assembled the robot Made it run

What we have seen so far?

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Varying the speed of the motor Play some tunes using the buzzer How IR works Making use of IR to find obstacles Make the bot avoid strangers Making it autonomous Some Advanced stuff

Today we will see..

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Varying the speed of the motor using PWM

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Playing tones in the buzzer

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We can generate a square wave at specified frequency using tone() function

Usage:

tone(pin, frequency, duration)

Playing sound

Teaching robot to avoid strangers

Two IR LED’s. One receiver, one transmitter Both face the same direction Keep transmitting IR waves If receiver receives waves, then there is a

obstacle Otherwise keep moving

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Let’s see some code

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Let’s get some food

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What are the limitations that we have faced so far?

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Using Delay

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Your microcontroller is going to sleep You can’t read or write while in delay Eg: You can’t detect an obstacle when the

bot is making a turn

Issues with delay

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How to fix it?

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Using Timer libraryhttps://github.com/JChristensen/Timer

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If we don’t read the pin, then we miss the value

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every(long period, callback); after(long duration, callback); oscillate(int pin, long period, int

startingValue); pulse(int pin, long period, int startingValue); update();

Methods in Timer library

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Interrupts

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Pin 2 and 3 Supports LOW, CHANGE, RISING, FALLING No software support is needed Can be removed as well

Hardware support

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Let’s see some code

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What if we need it on other pins?

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Software Interruptshttp://code.google.com/p/arduino-pinchangeint/

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Can be used on any pin

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Let’s see some code

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Making your robot follow a line Making your robot stay in a table Replace IR with ultrasound sensor Control the bot remotely using RF

Some ideas to try

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Controlled it using Android phone Controlled it using JavaScript and

WebSockets Controlled it using Bluetooth Controlled it using RF Added a missile launcher to it

https://github.com/sudar

Things I have tried

Links

Arduino – http://arduino.ccAsimi – A simple bot using Arduino

http://hardwarefun.com/project/asimiGetting started with hardware programming

http://hardwarefun.com/tutorials/getting-started-with-hardware-programming

Getting started with Arduino http://hardwarefun.com/tutorials/getting-started-with-arduino-and-avr

Questions

Thank You

Sudar Muthu (@sudarmuthu)http://hardwarefun.com/arduino-workshop

https://github.com/sudar/arduino-robotics-workshop