Adafruit Industries Adafruit Industries Short Flex/Bend Sensor
These sensors are easy to use, they are basically resistors that change value based on how much their flexed. If they're unflexed, the resistance is about ~25KO. When flexed all the way the resistance rises to ~100KO. They're pretty similar to FSRs so following this tutorial will get you started. You can use an analog input on a micro-controller (with a pullup resistor) or a digital input with the use of a 0.1uF capacitor for RC timing.
Adafruit Industries Short Flex/Bend Sensor
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