Several sensors have been considered now to get the best response for the LilyPad to play the meditation sounds.
1: LIGHT SENSOR
- This sensor works great with the LilyPad MP3 and has code readily available on how to tie the two together.
- Needs to have a well-defined change in light source to properly work.
- Not ideal for the purposes of this wearable because what if someone is deciding to meditate in a dark room? That would render this sensor absolutely useless.
2: TEMPERATURE SENSOR
- The code for the light sensor can be dissected to work with the temperature sensor with a bit of patience.
- Like the light sensor, it needs to have a well-defined change in temperature to be accurate.
- Not ideal for the purposes of this wearable because the sensor sits on/close to your skin within the garment so when you put your hand on/over the sensor the temperature change is not significant at all since your body is surrounding it at all times.
3: MPR121 Capacitive Sensor
- This sensor required a significant amount of hacking and dissecting the code to re-program the LilyPad
- The SJ1/SJ2 needed to be spliced in order to make the T3 and T2 trigger nodes read as SCL/SDA inputs
- Errors get thrown about 3-4 seconds into playback because the FTDI board is being used to power and talk to the LilyPad MP3 vs. a lithium battery
- The sensor has 12 nodes and is quite clunky to sew into a garment. In addition, this project only requires 2 nodes
- The capacitive nature of the MPR is incredibly sensitive, the nodes will even pick up external sounds/vibrations as touch triggers causing mis-reads and uninitiated triggering
- Setting the threshold to control the sensitivity of this could work, but still, once on the human body there are too many movements of the body to truly be able to control this and thus the nodes could misfire sounds not intended to be played.
4: Conductive Fabric Button
- This works with the LilyPad Mp3 as a point-to-point trigger player as the board is intended to do
- No dissecting or hacking of coding is necessary, just some creativity with button creation and implementing it into the garment
- Can make as many buttons as needed, in this case, 2
- Buttons can be made of lightweight conductive fabric and thread
I HAVE A WINNER!
Next steps are to come up with good locations to place the conductive fabric button on the garment and how best to connect them back to the LilyPad Mp3 board.