Book Image

Raspberry Pi for Secret Agents - Third Edition

Book Image

Raspberry Pi for Secret Agents - Third Edition

Overview of this book

This book is for all mischievous Raspberry Pi owners who’d like to see their computer transform into a neat spy gadget to be used in a series of practical pranks and projects. No previous skills are required to follow along, and if you’re completely new to Linux, you’ll pick up much of the basics for free. We’ll help you set up your Raspberry Pi Zero, Raspberry Pi 2 and Raspberry Pi 3 and guide you through a number of pranks and secret agent techniques that are so inconspicuous yet high on mischief. You’ll learn how to configure your operating system for maximum mischief and start exploring audio, video, or Wi-Fi techniques. We’ll show you how to record, listen, or talk to people from a distance and how to set up your own phone network. Then, you’ll plug in your webcam and set up a motion detector with an alarm and find out what the other computers on your Wi-Fi network are up to. Once you’ve mastered the techniques, we’ll combine them with a battery pack and GPS for the ultimate off-road spy kit.
Table of Contents (7 chapters)

Make your computer do the talking

Why should we humans have to exhaust ourselves yapping into microphones all day when we can make our computers do all the work for us? Let's install eSpeak, the speech synthesizer:

pi@raspberrypi ~ $ sudo apt-get install espeak

Now let's make the Pi say something:

pi@raspberrypi ~ $ espeak "I'm sorry, Dave. I'm afraid I can't do that."

If you receive warnings from ALSA whenever you run espeak, these can be safely ignored.

We could also make it read beautiful poetry in a French accent from a file:

pi@raspberrypi ~ $ espeak -f /etc/motd -v french

Or combine espeak with other applications for endless possibilities, as shown here:

pi@raspberrypi ~ $ ls | espeak --stdout | sox -t wav - -d reverb 99 50 0

To write the resulting speech to a WAV file, use the -w argument:

pi@raspberrypi ~ $ echo "It's a UNIX system. I know this." | espeak -w iknow.wav

Finally, to get a list of the different voices available, use the --voices and --voices=en arguments.