Book Image

Learning Javascript Robotics

By : Kassandra Perch
Book Image

Learning Javascript Robotics

By: Kassandra Perch

Overview of this book

There has been a rapid rise in the use of JavaScript in recent times in a variety of applications, and JavaScript robotics has seen a rise in popularity too. Johnny-Five is a framework that gives NodeBots a consistent API and platform across several hardware systems. This book walks you through basic robotics projects including the physical hardware builds and the JavaScript code for them. You'll delve into the concepts of Johnny-Five and JS robotics. You'll learn about various components such as Digital GPIO pins, PWM output pins, Sensors, servos, and motors to be used with Johnny-Five along with some advanced components such as I2C, and SPI. You will learn to connect your Johnny-Five robots to internet services and other NodeBots to form networks. By the end of this book, you will have explored the benefits of the Johnny-Five framework and the many devices it unlocks.

Related Content you might be interested in

Current Title:

Small book image
Learning Javascript Robotics
Kassandra Perch
Nov, 2015 | 160 pages
No titles found
Table of Contents (11 chapters)
Preface
Preface
What this book covers
What you need for this book
Who this book is for
Conventions
Reader feedback
Customer support
Free Chapter
1
1. Getting Started with JS Robotics
1. Getting Started with JS Robotics
Understanding JS Robotics, NodeBots, and Johnny-Five
Setting up your development environment
Hello, World! – Blinking an onboard LED
Summary
2
2. Working with Johnny-Five
2. Working with Johnny-Five
What you'll need for this chapter
How a Johnny-Five program works
Understanding events in Johnny-Five
Wiring up an external LED
Using the Read-Eval-Print-Loop (REPL)
Summary
3
3. Using Digital and PWM Output Pins
3. Using Digital and PWM Output Pins
What you'll need for this chapter
How GPIO pins work
Multiple pins with several LEDs
Using PWM pins with the Piezo element
Summary
4
4. Using Specialized Output Devices
4. Using Specialized Output Devices
What you'll need for this chapter
Outputs that require multiple pins
Checking compatibility with Johnny-Five
Obtaining documentation, wiring diagrams, and so on
Project – character LCD display
Summary
5
5. Using Input Devices and Sensors
5. Using Input Devices and Sensors
What you'll need for this chapter
How analog input pins work
Johnny-Five sensor events
Using basic inputs – buttons and potentiometers
Using sensors – Light and Temperature
Summary
6
6. Moving Your Bot
6. Moving Your Bot
What you'll need for this chapter
The different kinds of servos and motors
Special concerns when using motors and servos
Wiring up servos and motors
Creating a project with a motor and using the REPL
Creating a project with a servo and a sensor
Summary
7
7. Advanced Movement with the Animation Library
7. Advanced Movement with the Animation Library
What you'll need for this chapter
What is the Animation API?
Looking at the Animation API
Writing Servo Animations
Animation events
Summary
8
8. Advanced Components – SPI, I2C, and Other Devices
8. Advanced Components – SPI, I2C, and Other Devices
What you'll need for this chapter
Why do we need the I2C and SPI protocols?
Exploring SPI (Serial Peripheral Interface) devices
Exploring I2C devices
External Devices
Summary
9
9. Connecting NodeBots to the World, and Where to Go Next
9. Connecting NodeBots to the World, and Where to Go Next
What you'll need for this chapter
Connecting NodeBots to the Web
Johnny-Five and the wide world of microcontrollers
Other JS libraries and platforms
Where to go from here
10
Index
Index

Wiring up servos and motors

Wiring up servos will look similar to wiring up sensors, except the signal maps to an output. Wiring up a motor is similar to wiring up an LED.

Wiring up servos

To wire up a servo, you'll have to use a setup similar to the following figure:

A servo wiring diagram

Tip

The wire colors may vary for your servo. If your wires are red, brown, and orange, red is 5V, brown is GND, and orange is signal. When in doubt, check the data sheet that came with your servo.

After wiring up the servo, plug the board in and listen to your servo. If you hear a clicking noise, quickly unplug the board—this means your servo is trying to place itself in a position it cannot reach. Usually, there is a small screw at the bottom of most servos that you can use to calibrate them. Use a small screwdriver to rotate this until it stops clicking when the power is turned on.

This procedure is the same for continuous servos—the diagram does not change much either. Just replace the regular servo with...

Previous Section
End of Section 6
Next Section