todbot blog » programming

How To Do Big Strings in Arduino

todbot — Fri, 20 Jun 2008 05:08:29 +0000

Arduino makes it pretty easy to store & use character strings, but those strings compete with your variables, so you can’t do as much. Here’s how to put big strings into read-only program memory and use them.

Lots of sketches can have big strings in them. Maybe you’ve built a little command-line interface or you’re storing small web pages (for net-connected Arduinos). Normally you do something like this:

char hellostr[] = "<html><head><title>hello world</title></head>" "<body><p align=center><h1>hello world</h1></p> [...]

“WiiChuck” Wii Nunchuck Adapter Available

todbot — Tue, 19 Feb 2008 02:41:17 +0000

Want to hook up a Wii Nunchuck to an Arduino but don’t want to cut up the cord on your Nunchuck? Yeah me too. So I made some of these:

It’s a small PCB that adapts the Wii Nunchuck connector to standard 4-pin header. I call it the “wiichuck adapter”. It plugs directly into the Arduino, no wiring necessary. You can get one too for $4.

Available from the following wonderful shops: - FunGizmos.com. FREE DOMESTIC SHIPPING. International shipping for $1 more. - Tinker.it (UK) - Little Bird Electronics (Australia) - Sparkfun. Ships domestic & internationally. [...]

In Processing, size() matters for Serial ports

todbot — Tue, 15 Jan 2008 04:20:45 +0000

Mark Allen of Machine Project is teaching an Arduino course using some of the notes from my Bionic Arduino class. He and his students were seeing in Windows XP & 2000, when trying to getting Processing to talk to Arduino, the cryptic error: gnu.io.PortInUseException: Unknown Application at gnu.io.CommPortIdentifier.open(CommPortIdentifier.java:354)

Both his class and Mark and I separately spent a lot of time trying to figure out what the problem was. Eventually we discovered that it’s because the sketch I had written had a setup() [...]

SpiroExplorer, a Spirograph toy

todbot — Sun, 04 Jun 2006 06:31:14 +0000

So I’ve written a tool that can turn any parametric equation into a series of Roomba movement commands. Mostly, anyway. The parametric equations I’m predominately focusing on are the hypotrochoid series of equations used in a Spirograph.

To explore the space of hypotrochoid curves I created SpiroExplorer, a simple Processing applet that lets you to adjust the equation parameters in real-time. You can do the following things while it’s drawing:

- left/right arrows change “r”, the radius of the inner moving circle - up/down arrows change “d”, the pen’s distance from center of the moving circle - ,/. changes “R”, the radius [...]

RoombaComm library, release 0.95

todbot — Fri, 02 Jun 2006 01:44:35 +0000

RoombaComm is Java library for communicating and controlling the Roomba. It works on any operating system that RXTX supports. This includes Mac OS X, Linux, and Windows. It also works with Processing. It will soon work with Flash and Max/MSP.

It’s been a work in progress for several months and has gotten a little better as I work through improving it for the book.

Several bugs have been fixed, particularly with respect to Bluetooth on Windows. See the README for some info on that.

Tested systems: - Mac OS X 10.4 (Tiger) : usb serial & bluetooth - Mac OS X [...]

RoombaComm: Roomba Control & Communications API, release 0

todbot — Wed, 15 Feb 2006 07:15:07 +0000

Update: new version of RoombaComm released

As mentioned previously, I’ve started on a library to make Roomba-to-host-computer interfacing easier. This is the zeroth release of such a library.

The goals of this library are: provide full access to the entire Roomba SCI protocol provide a set of higher-level functionality on top of the SCI protocol create a library that is as cross-platform as possible provide interfaces to high-level languages/environments like Java, Flash, Processing, Max/MSP, etc. allow someone who’s not an expert programmer utilize a rapid development environment like Processing to quickly manipulate the Roomba.

Java was chosen as a language, [...]

Roomba Processing UI

todbot — Mon, 30 Jan 2006 22:12:34 +0000

Been playing around with Processing to act as the Roomba telemetry console. Here’s a little playable mock-up of what it might look like: Click to play with it. It’s sorta like a Virtual Roomba!

Roomba Hacking via Serial Tether

todbot — Wed, 25 Jan 2006 08:39:20 +0000

Note: This post is pretty old and I’ve been continuing work on Roomba software. Note: For a more readable take on this, see this Makezine artcicle

A week ago I got my OSMO//hacker Roomba firmware updater from iRobot. It worked like a charm, giving me a serial port to fully control the Roomba.

An interface was needed however, since the crazy mini-DIN 7-pin on the Roomba is very unstandard. So the first attempt at a robust interface between a Roomba and a standard PC serial port is my Roomba Serial Interface:

The Roomba Serial Connector It seems people are confused by the mini-DIN 7-pin connector, [...]

Finally, something about the US government I’m proud of…

todbot — Tue, 27 Apr 2004 03:17:00 +0000

Dictionary of Algorithms and Data Structures