It was time again to talk at the Good School ‘Camp Digital’ about the Internet of Things. Instead of choosing a real world example I choose to revive the good old ‘Twitballon‘ and create a new and improved version.
Twitballoon is a simple Arduino installation, which raises a balloon according to the activity of a certain keyword on twitter. The old version was using a hacked servo to move the ballloon but the servo had real problems with temperature stability. Due to the great opportunity to bring the Trinamic stepper driver chips to Arduino the servo was replaced by a stepper motor.
The basic principle of the Arduino sketch is real simple: The Arduino is connected to the internet via the Ethernet Shield and uses the Twitter Streaming API to permanently search for tweets with a certain keyword. A Tweet raises the level of the balloon for a certain amount and over time the position of the ballloon is lowered again. By this the position of the balloon reflects the activity on Twitter regarding the selected topic.
The stepper motor is driven by an experimental Trinamic breakout board. Interactive Matter provides a first version of the Arduino library for the TMC260/1/2 chip of Trinamic. The Trinamic chip makes driving a stepper motor a breeze. It offers a very detailed configuration, adapting the driver exactly to the given stepper motor, giving a very sielnt and precise control over the stepper. This is a little bit overkill for this project but in the end it made the positioning of the balloon very easy.
The look of Twitballoon 2 is intentionally rough and industrial to give it a technical yet humble appearance. In the end it was a very nice and conversational piece, communicating the playful aspects of tinkering.