About The Flex Sensors - richar66/FlexSensors-Midterm GitHub Wiki
##Spectra Symbol Flex Sensors Flex sensors can come from many different brands, for this project Spectra Symbol flex sensors are used. They can be purchased in a variety of sizes ranging from one to five inches. The sensors can be uni-directional or bi-directional and go from about 10k ohms (+/- 30%) when flat to at least twice the flat resistance when fully bent. A 2.2 inch one and two 4.4 inch sensors are used here for the thumb, pointer and middle finger respectively. All three are uni-directional and can be seen in the image below. For the bend to be detected the side with the squares needs to be facing out in the bend.
The sensors are very durable, effective for a life cycle of >one million bends. They are accurate and within a temperature range of -35 degrees Celsius to 80 degrees Celsius.
###How to Purchase The Spectra Symbol flex sensors can be purchased online through Amazon, SparkFun, Mouser Electronics, or DigiKey. Spectra Symbol can also customize sensors for specific uses. The 2.2” sensors cost $7.95 and the 4.4” sensors cost $12.95.
###How to Use Spectra Flex Symbols The flex sensors have two tabs for soldering that extend off the sensor to allow easy mounting. One side has a thin tan end that goes from the top of the sensor all the way to the soldering tab, this end will be connected to the analog input pin, resistors for a defined voltage divider, and then ground. The other end goes from the square sections of the sensor to the soldering tab and is connected to power. Using a constant input voltage with the constant resistance on the other side of the analog input pin, voltage divider allows the varying resistance of the flex sensor to be read in through the analog pin as a voltage so the code can be designed to carryout desired tasks for the different readings.
Common Uses
Flex sensors are commonly used in toys, gaming devices, safety switches, robotics, measuring devices and more. The uni-directional or bi-directional options allow for an even wider variety of uses. In this project they are used to detect finger bend so uni-directional is preferred.
Sources:
Citation: [1]S. SYMBOL, "Flex Sensor Manufacturers | Spectra Symbol", Spectrasymbol.com, 2016. [Online]. Available: http://www.spectrasymbol.com/flex-sensor. [Accessed: 15- Feb- 2016].