Page 61 - Hacking Roomba

42 Part I — Interfacing

Alternative #1: RoombaDevTools RooStick

The industrial robot company RoboDynamics created the RoombaDevTools site (http://
roombadevtools.com) to supply Roomba interface adapters and other Roomba hacking
products. One of the most useful products is RooStick, a USB version of the serial tether. It
functions exactly the same as the serial tether, appearing as a serial device to the OS (Windows,
Mac OS X, or Linux). It is available for around $25, with an accompanying 7-pin Mini DIN
for about $16. Be sure to use the Mini DIN cable from RoboDynamics unless you want to per-
form a pin-by-pin verification and rewiring of a non-approved cable. The current 8-pin Mini
DIN cables from Jameco will not work without modification. To be safe, always use the
RoboDynamics cable.
Demonstration code with source is provided in Visual Basic for Windows computers, available
for download from the RoombaDevTools web site. Figure 3-1 shows what RooStick looks like.

FIGURE 3-1: RooStick from RoombaDevTools

Alternative #2: Cell Phone Sync Cable Hack

A potentially easier serial tether to build is to use a USB cell phone sync cable. Before pervasive
Bluetooth and built-in USB ports on phones, phones had serial ports to allow data syncing. Of
course now computers may not have a serial port on them, so the sync cable for these phones
has evolved into a USB device with an embedded USB-to-serial converter in it.
These sync cables are currently available at Radio Shack for about $22 as a Future Dial Mobile
Phone Data Cable. They are easily hackable to provide a 0–3.3V positive-logic serial port.
This hack was originally discovered by the Linux router hackers, as they wanted access to the
0–3.3V serial console of these devices. For use with Roomba, some simple voltage converters
are usually needed to convert the 0–3.3V used by the cell phone to the 0–5V used by Roomba.