Page 280 - Hacking Roomba

Chapter 13 — Giving Roomba a New Brain and Senses 261

It’s tempting to skimp and not get a box of pre-cut jumper wires. Don’t do it. It’s possible to
cut and strip wires yourself (and necessary if you run out of pre-cut wires), but using just any
sized wire makes for an ugly and hard-to-read circuit. The ill-fitting wires move around, put-
ting stress on the breadboard holes. Making jumper wires takes a lot of time, which is kind of
beside the point of using a solderless breadboard. Get a box of pre-cut jumper wires and you’ll
be a much happier hacker.

Alternatives

Although the circuits presented in this chapter are both simpler and easier to build than the pre-
vious projects, even easier ways to re-program your Roomba are emerging. RoombaDevTools.com
is working on two boards that are functionally very similar to the Basic Stamp and Arduino
boards. They are:

RooStamp: A carrier board for Basic Stamp 2 that interfaces to Roomba. It is
Bluetooth-optional with servo ports and GPIOs exposed to the user, and it is powered
by the Roomba battery.
RooAVR: A high-end 16-bit Atmel AVR processor with plenty of I/Os, Bluetooth
onboard, A2Ds, URART, JTAG, and servo ports, also powered by the Roomba.

Both of these boards can also be powered externally if your project needs to draw more current
than Roomba can supply. The RooAVR uses the same type of microcontroller as Arduino, so it
should be possible to use the Arduino programming environment with it.
If wiring up a microcontroller to your Roomba is not your cup of tea and you want to get
started immediately making an autonomous robot, check out RoombaDevTools.com for these
devices. But hooking up a little computer to Roomba isn’t so hard really, as you’ll see.

Adding a New Brain with the Basic Stamp

The Basic Stamp was created by Parallax in the early 1990s to address a persistent problem of
embedded systems design: making it easy to use. Because microcontrollers are so self-contained,
you couldn’t just add a monitor and keyboard to them to see what’s going on. Instead you
needed some sort of development system, usually costing thousands of dollars. When you got
the development system, learning the strange non-standard languages used to program the
microcontroller was daunting. It could be months before you get a working system. And even if
you could get all that working, acquiring the microcontrollers themselves was quite difficult
unless you were a large company that wanted to buy 10,000 of them.
Parallax solved these problems by taking a common microcontroller, placing it on a hobbyist-
friendly carrier board and writing a BASIC language interpreter for it. Now anyone who could
program in BASIC could buy a single Basic Stamp and get a tiny stamp-sized microcontroller
running a program they wrote, and do it in an afternoon. It was a revolutionary way of thinking
about microcontrollers and for the past decade the Basic Stamp has been the standard in
microcontrollers for hackers.