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: 13045

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

Profile IconJack Gromek, pratik and KEKELI LOGAH joined GarageLab (arduino, electronics, robotics, hacking)
16 hours ago
GarageLab posted a blog post

Stanford’s cheap nanomaterial filter could solve the air pollution problem

The rapidly increasing industrialization in many parts of the world comes with economic benefits,…See More
16 hours ago
GarageLab posted a blog post

Blub Uno Clock Displays Time with One Nixie Tube

We’ve seen our share of Nixie tube clocks, but the Blub Uno is different. This is a clock that…See More
yesterday
GarageLab's blog post was featured

LEGO X Converts Creations into 3D Models in Real Time: Body and Soul

Created by Gravity Research Club, LEGO X creates a 3D model of whatever you’re building while…See More
Wednesday
sathiyakumar is now a member of GarageLab (arduino, electronics, robotics, hacking)
Tuesday
GarageLab posted blog posts
Tuesday
Profile Iconaymen hleli, gunawan eko, Dean Sanders and 1 more joined GarageLab (arduino, electronics, robotics, hacking)
Monday
GarageLab posted a blog post

Street Fighter Played with Pianos: Sound Fighter

Back in 2014 we saw an piano that was turned into…See More
Monday
GarageLab posted blog posts
Feb 20
Profile IconRobert Choi and Pierre Gelinas joined GarageLab (arduino, electronics, robotics, hacking)
Feb 20
David Wachter commented on GarageLab's blog post DARPA is developing a sensing bionic hand
"This would be nice for all of the military amputees that have been 'produced' since the…"
Feb 18
GarageLab's blog post was featured

AirBoard: The Flying Segway

Currently up for funding on…See More
Feb 18
GarageLab posted a blog post

DARPA is developing a sensing bionic hand

Not content just to chip in creating better mind-controlled bionic limbs, DARPA is focusing on…See More
Feb 18
Profile IconAmr Anwar and recca joined GarageLab (arduino, electronics, robotics, hacking)
Feb 18
GarageLab posted a blog post

Voltera V1 Circuit Board Printer: Print-A-Sketch

The latest in the growing niche of circuit board printers, the Voltera V1 can print up to two…See More
Feb 16
GarageLab posted a blog post
Feb 13
Profile IconBill Meng and Prem Patel joined GarageLab (arduino, electronics, robotics, hacking)
Feb 13
John R. replied to awet kidane's discussion how can i simulate sd card with arduino uno in proteus
"Awet, I am not entirely sure what you are trying to do or why, but you may want to check into an…"
Feb 11
GarageLab posted blog posts
Feb 11
Profile Iconsajol, daniel gabriel, Alex Rosas and 3 more joined GarageLab (arduino, electronics, robotics, hacking)
Feb 9

© 2015   Created by Marcelo Rodrigues.

Badges  |  Report an Issue  |  Terms of Service