Arduino - Make a Flex Sensor for Robotic Hand (Cheap and Simple)

by MertArduino in Circuits > Arduino

25084 Views, 190 Favorites, 0 Comments

Arduino - Make a Flex Sensor for Robotic Hand (Cheap and Simple)

Arduino Tutorial 21 : Make a Flex Sensor for Robotic Hand (Cheap and Simple)

In this tutorial, we will learn how to make and use a flex sensor.

We will control servo motor with a flex sensor.

Flex sensors are passive resistive devices that can be used to detect bending or flexing. The flex sensor shown in this tutorial is a flex sensor that decreases its resistance in proportion to the amount it is bent in either direction.You can easily make a sensor wider and longer depending upon your project.

Required Materials

vlcsnap-2017-01-08-18h07m02s185.png
vlcsnap-2017-01-08-18h07m11s540.png
vlcsnap-2017-01-08-18h07m21s621.png

- Paper

- Flexible Cardboard or Plastic

- Pencil

- Aluminum Foil or Aluminum Tape

- Wires

- Hot Silicone or Solder

A 2.2 inch flex sensor can range in price from $ 10 to $ 50.

If we think that at least 5 flex sensors are used in a robotic hand project, the cost will be quite high.

$ 20 * 5 flex = $ 100

Creating a Flex Sensor

vlcsnap-2017-01-08-18h07m36s034.png
vlcsnap-2017-01-08-18h07m49s295.png
vlcsnap-2017-01-08-18h08m17s888.png
vlcsnap-2017-01-08-18h08m25s224.png
vlcsnap-2017-01-08-18h08m40s038.png
vlcsnap-2017-01-08-18h08m50s762.png
vlcsnap-2017-01-08-18h09m05s207.png
vlcsnap-2017-01-08-18h09m12s089.png
vlcsnap-2017-01-08-18h09m34s789.png

  • I do it according to the size of my own hand fingers
  • I cut paper according to these dimensions
  • With a pencil, the front and back of the paper are drawn in such a way that there is no space left.
  • The greater the density, the better the resistance value we will have.
  • The value of resistance, which varies with the curl of the paper, will give us the amount of flexibility.
  • We cut two pieces of cardboard according to the size of our paper.
  • We stick aluminum on one side of the cardboard parts.
  • Connect wires to the aluminum strips to get value from the sensor.
  • Two aluminum strips should not touch each other.
  • The same goes for Wires!
  • For a robotic hand we make five in this way.
  • I used silicone on the surface to prevent damage.

Connection and Circuit Diagram

vlcsnap-2017-01-08-18h11m28s533.png
vlcsnap-2017-01-08-18h09m52s986.png
vlcsnap-2017-01-08-18h10m01s834.png

With this circuit diagram we will read the value from the sensor and turn the sevo.

Every sensor we make will show resistance at different values.

Code

vlcsnap-2017-01-08-18h10m11s809.png
vlcsnap-2017-01-08-18h10m31s638.png
vlcsnap-2017-01-08-18h10m55s891.png
vlcsnap-2017-01-08-18h11m16s105.png
vlcsnap-2017-01-08-18h06m35s366.png

  • With this sample code we will read the value from the sensor.
  • Every sensor we make will show resistance at different values.
  • By testing between 0 and 1023 we will find the output value of the sensor.
  • We are moving the sensor ... When the sensor is at 1023, the Servo position will be 90 degrees.
  • The sensor has a minimum value between 1018 and 1020.
  • We make the sensor range from a minimum of 1020 to a maximum of 1023
  • Thus, between these two values we can move the servo motor 0 to 90 degrees.
  • 0 degrees at 1020 - 90 degrees at 1023 As you can see, we can get 1018 value.
  • We can make the minimum value of the sensor 1018.
  • We found the range of values for all the sensors we did this way.

Get the Example Code