I was approached by WhiteLight Ltd to create a device that allowed guests to interact with a light installation in an unusual way – via their pulse. The brief was something that would allow each person to control a 280m long installation of RGBW uplighters in a tunnel using their heart rate. I made this Pulse to DMX sensor using a ‘Pulse Sensor Amped’ from Pimoroni, it outputs an analog voltage when a finger is placed over the pad. I chose this because electrically isolated from the user, so I didn’t have to worry too much about other forms of electrical isolation from the rest of the system that the ECG type of sensors need. The sensor is connected to a unit that analyses the waveform, and converts into 5 DMX channels, BPM, Pulse trigger, Pulse present (or enable), raw data, and a variable frequency sine wave.
The installation was actually controlled by a GrandMA console, and the Pulse DMX sensor was used as an input to trigger a one-shot effect, and a contact closure for sound, to trigger a heart beat type sound.