|
Available Languages
|
|
|
Introduction
|
|
In this "How to" tutorial you will learn how to use a flex sensor with Arduino uno.
A flex sensor uses carbon on a strip of plastic to act like a variable resistor. The resistance changes by flexing the component. The sensor bends in one direction, the more it bends, the higher the resistance gets. In this example we will use a flex sensor to fade an led. |
What you will need - Hardware
|
For this tutorial you will need:
|
|
The Circuit
The connections are pretty easy, see the image above with the breadboard circuit schematic.
The code
Here's the code,
A flex sensor has a range from about ~10K to ~35K, that means it won't give us a full 0-5 volt range (or 0-1023 analog value). Try to use the serial monitor below to find out what analog value you will take while you bending the sensor. It supposed to be between 700 to 900.
How it works:
Read analog value from flex sensor
-> value=analogRead(flexPin);
Map analog values 700-900 to pwm values 0-255
-> value = map(value, 700, 900, 0, 255);
Send pwm value to led
-> analogWrite(ledPin, value);
A flex sensor has a range from about ~10K to ~35K, that means it won't give us a full 0-5 volt range (or 0-1023 analog value). Try to use the serial monitor below to find out what analog value you will take while you bending the sensor. It supposed to be between 700 to 900.
How it works:
Read analog value from flex sensor
-> value=analogRead(flexPin);
Map analog values 700-900 to pwm values 0-255
-> value = map(value, 700, 900, 0, 255);
Send pwm value to led
-> analogWrite(ledPin, value);
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 | /* How to use a flex sensor/resistro - Arduino Tutorial Fade an LED with a flex sensor More info: http://www.ardumotive.com/how-to-use-a-flex-sensor-en.html Dev: Michalis Vasilakis // Date: 9/7/2015 // www.ardumotive.com */ //Constants: const int ledPin = 3; //pin 3 has PWM funtion const int flexPin = A0; //pin A0 to read analog input //Variables: int value; //save analog value void setup(){ pinMode(ledPin, OUTPUT); //Set pin 3 as 'output' Serial.begin(9600); //Begin serial communication } void loop(){ value = analogRead(flexPin); //Read and save analog value from potentiometer Serial.println(value); //Print value value = map(value, 700, 900, 0, 255);//Map value 0-1023 to 0-255 (PWM) analogWrite(ledPin, value); //Send PWM value to led delay(100); //Small delay } |
|
|
Download the code from here and open it with Arduino IDE. Open the serial monitor from tools menu of Arduino IDE to test it.
| ||
|
You can make your own modifications to the code, for example, you can change "700-900" values in map function. |
|
Well done!
|
|
You have successfully completed one more Arduino "How to" tutorial and you learned how to use a flex sensor with Arduino. I hope you liked this, let me know in the comments.
