If you are not so keen on spending the £80 needed to book the V&A workshop then why not try a bit of self-learning? There are tonnes of videos and tutorials to be found online.
What is Arduino?
“an open-source physical computing platform based on a simple microcontroller board, and a development environment for writing software for the board”. In other words, a circuit system that connects to a power source (either your computer or even a battery) and other devices based on your needs. You can, for example, connect sensors to your board to detect certain aspects of the environment (such as sound or movement) and then have this converted into data to manipulate as you wish. You can use the Arduino coding environment (download it from their website here: http://www.arduino.cc/en/Main/Software) or a coding environment such as Processing to produce particular actions based on variables within the gathered data.
Learn more about Arduino here: http://www.arduino.cc/en/Guide/Introduction
Check out demos and tutorials on the Processing website to get you started: https://processing.org/tutorials/