I was invited to be a speaker at O’Reilly Where 2.0 Conference. It’s a conference mostly about mapping technologies, location-based services, and interesting new location-aware mobile apps.

I spoke about RFID and NFC, in the context of the release of the new NFC-capable Android phone, the Google Nexus S. Having an RFID reader in a phone could cause a big change in how we interact with the world around us. I talked about what RFID and NFC technologies are, how they work, some examples of them in the world and on Android, and how to add [...]

I love Arduino but its lack of wireless bugs me. And it sucks that WiFi Shields for the Arduino cost as much a cell phone. I want something cheap. Turns out, small, cheap WiFi routers like the Asus WL-520gu can run the DD-WRT Linux firmware and act as serial-to-network gateway for Arduinos (or most any other USB device). Here’s how to do it.

(Hey, is this a Wifi-controlled BlinkM? I think it is.)

A quick video showing a router acting as a serial-to-network gateway:

This is not that new of a concept, hacking Linux onto a router for some [...]

All BlinkM-family devices can have their firmware updated. This makes them great for tiny development boards for ATtiny processors. ReflashBlinkM is an application that makes it easy to put back the original firmware or update a BlinkM to the latest firmware.

Previously you needed an AVR ISP programmer like the AVRISPmkII or the USBtinyISP. Thanks to the ArduinoISP sketch that ships with Arduino, if you have already have an Arduino, you can easily reflash your BlinkM with new firmware.

The ReflashBlinkM application is a tool for Mac OS X and Windows that uses ArduinoISP to help you reflash BlinkMs to their default [...]

Ever wanted to use any pair of pins for I2C on Arduino, not just the dedicated pins on Analog 4 & 5? Me too, so I made a quick little Arduino library called “SoftI2CMaster”, available in the “blinkm-projects” Googlecode repository.

Get it here: SoftI2CMaster.h, SoftI2CMaster.cpp.

It’s still a work in progress, but it can write data pretty successfully and do it over longer cables than normal.

For the VIMBY/Scion Hackerspace Challenge, I created an array of BlinkM MaxM-powered accent lights for the device we made. Because the I2C cable was longer than a few feet, the normal Wire library that [...]

At this years Sketching in Hardware conference, I gave a talk on the general approach I used to create LinkM, ThingM’s USB-to-I2C adapter for programming and controlling BlinkMs. I called it “Hacking USB HID for Easy Tethered Ubicomp” (4.8MB PDF) to give it a form that fit within some of the larger issues I’ve been dealing with in creating easily usable ubiquitous computing devices.

USB has many different (and confusing) aspects to it. I’ve long advocated the creation of a set of libraries and patterns to make “driverless” USB a reality. A sort of training wheels for USB. [...]