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# School of Maaa Day 2 - Voltage Dividers

Theory behind making your own variable resistor sensors.

August 14, 2014

## Transcript

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.

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

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.