Proposal - richar66/FlexSensors-Midterm GitHub Wiki

#Flex Sensors Midterm Proposal This project focuses on reading the varying resistance of three Spectra Symboflex flex sensors as they are flexed while attached to the pointer finger, middle finger, and thumb of a right handed glove. The flex sensors work by applying a constant voltage through the sensor and reading the changing output based on the increased resistance as the sensors are bent.

For my midterm, if only the thumb is bent, a blue LED will light up, if the thumb and pointer finger are bent a blue and yellow LED will light up, if a thumb, pointer finger, and middle finger are bent a blue, yellow and red light will turn on and if the middle finger and thumb are bent a blue and red light will turn on. If no fingers are bent a green LED will turn on.

For my group’s final project, the flex sensors will be used to detect clicking and scrolling of a bluetooth mouse. Flexing the thumb will execute a “click”, if the pointer finger is bent while clicking it will send a left-click signal, if the pointer and middle fingers are bent while clicking it will send a right-click signal, and if no fingers are extended while clicking it will act as scrolling techniques such as the grab and scroll on a pdf.

The parts for this project are an Arduino Uno, two 4.5 inch flex sensors, one 2.2 inch flex sensor, six 1k ohm resistors, four LEDs, four 220 ohm resistors, a breadboard and wires. Each of the flex sensors is connected to an analog pin so the changing voltage can be read through the serial monitor. The 1k ohm resistors are used to lower the readings for the flex sensors so they are in the range of the serial monitor to make reading and using the values easier. The 220 ohm resistors are used to protect the LEDs that light up according to the different combination of bent fingers. The flex sensors will be attached to the outside of a glove so the hand movements will be detected from the user wearing the glove and flexing their fingers.

The code consists of if statements that check what finger combinations are occurring and set the digital pins connected to the LEDs high or low to turn them on and off. The straight sensor has a resistance of about 10k ohms and a bent sensor has almost 20k ohms. The analog pins read in the voltage that varies with the increased resistance that comes with a bent sensor or normal, base reading that comes from a straight sensor. When a certain condition is met the digital pins output high or low signals to turn the proper LEDs on or off.