While it's most common to see the Arduino used whole in people's projects, as an off-the-shelf means of driving or sensing something, the open-source nature of the project means that it can also be used to build something entirely new yet compatible. Nick Johnson, whose circuit pattern trading cards we've highlighted in the past, has done exactly that with the Tsunami: a signal generator, analyser, and experimentation kit designed with Arduino compatibility in mind. Based on the same processor as the Arduino Leonardo, the Tsunami boasts a Direct Digital Synthesis chip capable of generating analogue signals in a simple and accessible manner. The result: a board which can be used with the Arduino IDE and which generates a square wave on one output and any wave of your choice on another - up to, Nick claims, 2MHz. An additional input gives frequency, amplitude and phase detection up to 8MHz, and phase, frequency and amplitude modulation is supported on both input and output. In short, it's a bit of a beast: suggested projects include creating a synthesizer or theremin, using it as a precise clock generator, encoding and decoding audio data, reading data from vintage computing cassettes, and even using it as a low-power radio transmitter. If any of those projects sound interesting, Nick is running a Kickstarter campaign to raise funds for the first mass-production run of the boards.
We've taken the versatile processor behind the Arduino Leonardo, and combined it with a Direct Digital Synthesis chip, which makes generating analog signals incredibly straightforward. Then, we've added on flexible input and output circuitry, and an easy to use software library, to make working with analogue signals as easy as blinking an LED.