School of Maaa Day 2 - Voltage Dividers

School of Maaa Day 2 - Voltage Dividers

Theory behind making your own variable resistor sensors.

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Becky Stewart

August 14, 2014
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Transcript

  1. Voltage Dividers

  2. Pressure Sensor Cushion Pauline Vierne http://etextile-summercamp.org/2014/pressure-sensor-cushion/

  3. LaceSensor Dresses Anja Hertenberger and Meg Grant http://lacesensorproject.com/

  4. Mi.Mu Gloves http://theglovesproject.com/

  5. Stretch Sensor

  6. Soft Potentiometers

  7. Squeeze Sensor

  8. Arduinos can only watch changes in voltage. ! Not changes

    in resistance or current.
  9. But we can turn a changing current or resistance into

    a changing voltage by being clever.
  10. Vin Vout GND GND R1 R2 Voltage Divider

  11. Vin Vout 5V GND GND R1 R2 Something between 5V

    and GND Voltage Divider
  12. Vin Vout 5V GND GND R1 R2 Something between 5V

    and GND Voltage Divider
  13. Vin Vout 5V GND GND R1 R2 Something between 5V

    and GND Voltage Divider = Vout Vin x R1 + R2 R2
  14. Vin Vout GND GND R2 Voltage Divider R1 knit sensor

  15. Vin Vout GND GND R2 Voltage Divider R1 knit sensor

  16. Voltage Divider

  17. Vin Vout GND R1 R2 Voltage Divider potentiometer *In this

    circuit, both R1 and R2 are changing when the knob is turned.
  18. Voltage Divider 1. Does the object change resistance when you

    interact with it? Check with a multimeter. 2. If does, create a voltage divider. Decide if you want the object to be R1 or R2. 3. Choose a static resistor that gives you the values you are looking for.
  19. Challenge Create an analog sensor using soft materials. Demonstrate it

    working with an Arduino.