specifications for the sensors for a botar

force sensor

• resolution: 7 bit
  • this is approximately the resolution of the human ear for loudness
• range of force: 0-? g
  • maximum should not be much greater than the force needed to hold a guitar or cello string to the fingerboard
• range of motion (how far you can depress (deform) it): 0-10 mm?
• linear over the whole length of the 'string'

position sensor

• function: senses position of the player's finger pressing the 'string'; if more than one finger is pressing the string, uses the position of the finger nearest the 'bridge' end of the sensor
• resolution: 5 bits/half-step
  • this is approximately the resolution of the human ear for pitch
• range of position:
  • length of a half-step: ~25 mm
  • length of a 'string': ~16 half-steps (~40 cm)
• linear over the whole length of the 'string'
  • this is different than a guitar or a cello, of course, but I prefer it

notes

• if the force sensor and the position sensor are not integrated (one sensor that detects both force and position):
  • the sensors must be stackable
    • the position sensor over the force sensor or vice versa
    • if the position sensor is placed over the force sensor
      • the position sensor must be pliable enough to allow the force sensor to detect the force of the player's finger
      • and vice versa
  • unless the position sensor is mounted at the 'bridge' end of the 'string'
    • as, for example, in a sonar or laser system
• the total depth of the sensor or sensors must not exceed the thickness of a guitar or cello neck
• the total width of the sensor or sensors used in one 'string' must not exceed the distance between strings on a guitar or cello
  • assuming the sensor(s) can be mounted flush (side by side with no gap between them required)

write Tom