My first milestone is to test out the sensors I’m interested in using.

Breath Sensor: for now I’m still unable to find any off-the-shelf one which can differentiate between inhale and exhale. Hence I went to the approach using homemade microphone to get audio and using Tristan Jehan‘s analyzer object with which I found the main difference of exhale and inhale is the brightness. Nice thing about using microphone is that I can also easily get the amplitude of the breath which is indicating the velocity of the breath.  Problem with this method is it needs threshold calibration each time you change the environment and homemade mic seems to be moody – unstable performance with battery..

Breath Sensor from kaikai on Vimeo.

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Muscle Sensor:  It works great on bicep although I don’t have big ones but the readings on face is subtle – it’s only effective for big facial expressions – face yoga worked. It also works for smiling, opening mouth, and also frowning (if you place the electrodes just right). During the experimentation, I figure it’s not quite a comfortable experience having sticky electrodes on your face but alternatives like stretching fabric + conductive fabric could possibly solve the problem which is my next step. Also, readings don’t really differentiate each other, meaning you won’t know if it’s opening mouth or smiling by just looking at the single reading. Either more collecting points need to be added, or it could be coupled with faceOSC which I think is more likely the way I’m going to approach.

FaceOSC: I recorded several facial expressions and compared the value arrays. The results show that the mouth width, jaw and nostrils turned out to be the most reactive variables. It doesn’t perform very well with the face yoga faces but it does better job on differentiating expressions since it offers you more parameters to take reference of.

Next step for me is to keep playing around with the sensors, try to figure out a more stable sensor solution (organic combination use) and put them together into one compact system.