When you write a book, any book, there’s a temptation to look back at it as an epic journey. After all, it takes months to write one, to do all the projects (twice, sometimes more), research, and so on. It might not seem that way to readers. Nevertheless, we have been on an epic journey. We started out just buying the right parts and getting the Pi running. Here at the end, we’ve been through enough Linux to get things done, leveraging the C++ you already knew from Arduinos, learned the ins and outs of WiringPi, learned some system programming, and learned how to attach projects to the Pi so the whole operating system can see them. Finally, we came full circle and built our own Arduino compatible connected to the Pi, for those times when nothing else will do. It’s been a journey. Hopefully, it’s been fun. The projects have been simple, but that’s because complexity just gets in the way when you’re trying to learn new concepts. You can add the complexity. You can make the Pi do new and amazing things. I’m just here to give you the tools and to help you add the Raspberry Pi to your toolbox. Where you go from here is up to you.
If you’ve enjoyed this book, I should mention I have another book with Apress called Junk Box Arduino, Ten Adventures in Upcycled Electronics. It digs much deeper into the Arduino world, and into hooking up all kinds of old ICs that you might find in the electronics junk that are too good to throw away but not useful anymore.
Credit Where Credit Is Due
As I’m sure you’re aware, it’s really tough to come up with new projects for Raspberry Pis (or Arduinos). In most cases, someone, somewhere, has done it before you. That’s a good thing. It’s the advantage of having a community. As a result, however, I need to acknowledge a few sources.
For Chapter 12, I used ideas from Mark Williams’ blog here: http://ozzmaker.com/program-avr-using-raspberry-pi-gpio/ and Lukáš Lalinský’s blog here: https://oxygene.sk/2015/02/using-raspberry-pi-as-an-arduino-avr-programmer/ .
For all matters C++, I leaned heavily on this site: http://www.cplusplus.com/doc/tutorial/files/ and various stackoverflow.com forums. If you ask a programming question in a Google search, Stackoverflow will probably have an answer. And perhaps a debate, minor flame war, and so on.
For socket programming, Eva M. Castro’s “Porting Applications to IPv6” HowTo was a godsend, and ultimately it was her approach, ported to C++, that I used. See http://long.ccaba.upc.edu/long/045Guidelines/eva/ipv6.html .
Parting Thoughts
I have a few other thoughts, mostly hints and tips that came up during the writing of the previous chapters, but that just don’t fit in the chapters. Instead, they’re here, and in no particular order.
Be Patient
Pis are incredible little computers for their price and size, but we’re spoiled by their desktop cousins that have many times more power. The Pi can do it. It just takes longer.
Label Your Pi
I can tell you from personal experience that almost nobody has just one Raspberry Pi. Label them, both in their configurations and preferably with a sticker or something on the hardware. Bonus points if you find a way to label the microSD cards. Does it sound like I had mixups? Reloaded the wrong microSD cards? Your ear has not failed you.
Use Terminal Applications When You Can
Most terminal apps hail from the bad old days when an entire campus might share a UNIX computer not much faster (except in disk I/O) than a Raspberry Pi. They’re very, very fast, even on a Pi Zero W.
Get a Real Drive
It’s entirely feasible to use your Pi as a backup desktop computer, but it’s much, much less painful if you have it use a real drive instead of a microSD card for most of its jobs. We’ve connected additional flash filesystems to the USB ports, but with a cheap USB-SATA adapter, you can hang a laptop drive from the same port. There are a number of ways to connect this up (Google it), but the best is probably to configure the Pi’s system chip to get everything from the USB drive. The Raspberry Pi 3 Model B (and presumably the modern Raspberry Pi 3 model B+) can apparently do this. I’ve done it the old way, where the kernel lives on the microSD card and mounts the external drive to the /root and /home filesystems. It works. Even a 5400RPM laptop drive is much faster.
Synergy
Right now, as I type this, there are three computers on my desk, including the Pi Zero W. I have room for one keyboard and one mouse (and expensive tastes in both). I’ve found the Synergy application to be incredibly useful for letting my Mac or my big Linux box serve this keyboard and mouse out to whatever Pi I have connected. I use the open source version, since the for-pay version does not support ARM platforms like the Pi. You can install a useable version on the Pi (1.4.16-2) with apt-get. Just turn encryption off. You can find more info here: https://sourceforge.net/projects/synergy-stable-builds/ . Be advised that the open source version of Synergy is not considered secure.