Capturing Data

PCBs

For the registration of the infrasound, I have created a replica of my left foot in glass. This foot has 5 piezo sensors behind the digits, connecting each one of them to an amplifier circuit on top of the glass foot. This circuit is a hacked version of the Piezo Film Pulse Sensor project developed to measure blood pressure using a piezo sensor[1]. I manipulated the circuit to use an Arduino[2] to process the signal of the sensors. The PCB circuits have a cut off frequency of 12/13 hertz and a low end response of 0.7 Hz. Once the circuits were built the tests showed that the circuit was able to register frequencies up to 22 Hz. The main challenge is the false positives of the circuit due to its instability. To avoid those false readings, the data was mapped and processed during the transmission from Arduino to Max MSP[3].

[1] Phoenix Ambulatory Blood Pressure Monitor Project Sub-project: Piezo Film Pulse Sensor (2005).  <http://www.phoenix.tcieee.org/004_Piezo_Film_Blood_Flow_Sensor/Phoenix_PiezoPulse.htm> accessed December 2015.

[2] Arduino. <https://www.arduino.cc/> accessed December 2015.

[3] Cycling’74 Max. <https://cycling74.com/products/max/> accessed December 2015.

Circuit Schematic
Circuit with cglass foot

     From the glass foot, I generate an infrasound sound file with the data of the sensors using Max MSP software. The vibrations of that sound file are reproduced through a subwoofer plate amplifier and several tactile transducers, between 7 and 12, depending on the size of the installation. This generates the vibration that the user will experience in the installation.