Introduction

Good news! DFRobot is launching 7 new flex sensors with different sensing areas, covering three kinds of shape: circle, square, and long strip. You can definitely find the one you want here.

These flex sensors feature great flexibility and easy to use, peel off the protection cover and stick the sensor on the surface we want to detect , then it works. Their advantages of recording the intensity and frequency of force make them widely used in all kinds of applications, such as, pressure switch, bed monitoring system, intelligent sneaker and medical device system.

The 7 flexible pressure sensors are made of ultra-thin film of excellent mechanical property, excellent conductive materials and nanometre pressure sensitive layers. There are thin film and pressure sensitive layer on the upper layer of the sensor, and thin film and conductive circuit on the lower layer. These two layers are glued together by double sided tape. When outside pressure applies to the active area, the disconnected circuit of the lower layer will be connected through the pressure sensitive layer of the upper layer, by which to convert pressure into resistance. The output resistance decreases as pressure increases.

The sensor is durable and designed to sense static and dynamic pressure in a pretty high respond speed.

Specification

Tutorial

We use flex sensor together with Arduino UNO mainboard in this tutorial, and the tutorial will demonstrate how does the serial port output change under different pressure conditions.

Requirements

Resistance vs Force

Resistance vs Force graph

When the outside force applies to the active area, the disconnected circuit of the lower layer will be connected through the pressure sensitive layer of the upper layer, by which to convert pressure into resistance. The output resistance decreases as force increases. That is to say, the sensor output different resistances under different force conditions. The relationship of resistance and force is shown in the above figure. The abscissa represents force and the ordinate is resistance. As the picutre shows, when the the force applying to the sensing area is too strong or weak, the slope will be correspondingly too large or small. So these sensors are more suitable for qualitative measure. There would be large data errors if using the sensor in quantitative measure.

Connection Diagram

Connection Diagram

Sample Code

/***************************************************
* Piezo Vibration Sensor 
* ****************************************************
* This example The sensors detect vibration

* @author linfeng(490289303@qq.com)
* @version  V1.0
* @date  2016-2-26

* GNU Lesser General Public License.
* See <http://www.gnu.org/licenses/> for details.
* All above must be included in any redistribution
* ****************************************************/
#define sensorPin A0
void setup() {
  Serial.begin(115200);
}

void loop() {
  int x=analogRead(sensorPin);
  Serial.println(x);
  delay(50); 
}

Expected Results

Serial Output Result

The serial data changes as above when we press the sensor. The serial data decreases linearly as the force increases. We recommend you use the sensor in qualitative measure.

FAQ

Q&A Some general Arduino Problems/FAQ/Tips
A Please click the topic link on DFRobot Forum.
A For any questions, advice or cool ideas to share, please visit the DFRobot Forum.

More Documents

DFshopping_car1.png Get Thin Film Pressure Sensor SKU_SEN0293/SEN0294/SEN0295/SEN0296/SEN0297/SEN0298/SEN0299 from DFRobot Store or DFRobot Distributor.

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