Tutorial: Flex Sensor with Arduino

On this tutorial, we will use the Arduino to read a flex sensor. The flex sensor is a device that changes its resistance proportional to its form, like this:

If the sensor is straight, it outputs 30k, it is flexed, 50k. With an Arduino board, make this circuit:

The resistor makes a voltage divider to make the reading possible. The analog input A0 is our signal.

Open the Arduino IDE and upload the following code. This code shows how many degrees the sensor is flexed.

// Flex sensor test program

// Mike Grusin, SFE, 2011
// This program is free, use it however you wish!

// HARDWARE:
// Make the following connections between the Arduino and the flex sensor
// Note that the flex sensor pins are interchangeable

// Sensor pin - GND
// Sensor pin - Analog In 0, with 10K resistor to +5V

// INSTRUCTIONS:
// Upload this sketch to your Arduino, then activate the Serial Monitor
// (set the Serial Monitor to 9600 baud)

void setup()
{
    // initialize serial communications
    Serial.begin(9600); 
}

void loop()
{
    int sensor, degrees;

    // read the voltage from the voltage divider (sensor plus resistor)
    sensor = analogRead(0);

    // convert the voltage reading to inches
    // the first two numbers are the sensor values for straight (768) and bent (853)
    // the second two numbers are the degree readings we'll map that to (0 to 90 degrees)
degrees = map(sensor, 768, 853, 0, 90);
    // note that the above numbers are ideal, your sensor's values will vary
    // to improve the accuracy, run the program, note your sensor's analog values
    // when it's straight and bent, and insert those values into the above function.

    // print out the result
    Serial.print("analog input: ");
    Serial.print(sensor,DEC);
    Serial.print(" degrees: ");
    Serial.println(degrees,DEC);

    // pause before taking the next reading
    delay(100); 
}

Upload the code and open the serial monitor to see the results.

That's it!

References:

http://www.sparkfun.com/products/10264

http://www.sparkfun.com/datasheets/Sensors/Flex/flex22.pdf

http://www.sparkfun.com/tutorials/270

Views: 15595

Tags: arduino, flex, sensor, tutorial

Comment

You need to be a member of GarageLab (arduino, electronics, robotics, hacking) to add comments!

Join GarageLab (arduino, electronics, robotics, hacking)

Latest Activity

GarageLab posted a blog post

ELECTRIC LAWN MOWER CONVERTED TO RC CONTROL

Not too many people like pushing a lawn mower around the yard, but unfortunately, it is a necessary…See More
9 hours ago
Profile Iconchiran sachintha and Blun Blun joined GarageLab (arduino, electronics, robotics, hacking)
9 hours ago
GarageLab posted a blog post

Codename Colossus: The HMC Boudicca

[Michael Sng], founder of [Machination Studio], wanted to create a toy line unlike anything the…See More
Friday
Fernando Rodrigues Pontes is now a member of GarageLab (arduino, electronics, robotics, hacking)
Friday
GarageLab posted blog posts
Jun 23
Profile IconSayed Akbar Rajaei Ramsheh, william sarte and Ahmed OUKERROUM joined GarageLab (arduino, electronics, robotics, hacking)
Jun 23
GarageLab posted a blog post

Dashboard in you simulator!

 Fans of driving simulator games not only play with steering wheels, gear shifters and pedals. Some…See More
Jun 22
Jesus M Andino commented on GarageLab's blog post Diabetes Has a New Enemy: Robo-Pancreas
"How will be the sugar regulated when there is a higher demand of it due to stress situations? "
Jun 19
GarageLab posted blog posts
Jun 19
GarageLab posted blog posts
Jun 17
AnalysIR posted a blog post

Porting AnalysIR firmware to Particle’s Photon platform

We have just finished porting our (single source) firmware from a range of other ‘Arduino’ type…See More
Jun 17
Profile Iconabin joseph, ATony and cocowei joined GarageLab (arduino, electronics, robotics, hacking)
Jun 17
Michael updated their profile
Jun 15
lovakiranvarma replied to Kringen's discussion MSP430 Launch Pad
"hi! Kringen even though Energia is promissing! But in my opinion it won't much helpful…"
Jun 14
GarageLab posted a blog post
Jun 12
AnalysIR posted a blog post

Simple Infrared PWM on Arduino, Part 2- RAW IR Signals

In Part 1 of this series, we demonstrated how to send signals using simple Infrared PWM on Arduino.…See More
Jun 12
Profile IconJesus M Andino, Aaron Armstrong and edmund joined GarageLab (arduino, electronics, robotics, hacking)
Jun 12
John Ruffing commented on GarageLab's blog post On your phone while driving an electric skateboard
"Well done!"
Jun 11
Profile IconCarlos Ito, Jorge Mario Zuleta and pd joined GarageLab (arduino, electronics, robotics, hacking)
Jun 11
GarageLab posted blog posts
Jun 10

© 2015   Created by Marcelo Rodrigues.

Badges  |  Report an Issue  |  Terms of Service