Control Servo Arm Using Force Sensitive Resistor

Hello Makers,

I'm back with another cool Instructable.

This Instructable is part of a series of Instructables with the NodeMCU, my previous Instructables shows you how to Interfacing FSR with NodeMCU, and lots more. So make sure, you check that first before trying out this.

So, let's get started !!

Step 1: Components Needed

All That You Need.

Hardware Required

NodeMCU
FSR (Force Sensitive Resistor)
Servo Motor
10K ohm resistor
Bread Board
Micro USB cable
Connecting Wires

Software Required

Arduino IDE (with ESP8266 Library installed)

Step 2: Descriptions

Servo motors are great devices that can turn to a specified position.

Usually, they have a servo arm that can turn from 0 - 180 degrees.

Generally FSR's are resistors that changes its resistance value (in ohms) depending on how much its force / pressure is applied on it.

Therefore, using NodeMCU, we control a servo arm to a specified position by applying force on FSR. As simple as that!

Interfacing Servo Motor with NodeMCU

Interface Force Sensitive Resistor to NodeMCU

Step 3: Circuit Wiring

No soldering skills are required as we will be using a breadboard.

FSRconnections are pretty easy, see the circuit diagram.

Servo connections :

Orange wire connects to Digital pin D2.

Brown wire connects to GND pin.

Red wire connects to 3v3 pin.

Step 4: Coding Time

CODE

#include <Servo.h>

Servo servo;

const int sensorOut = A0; // Pin A0 to read analog input

//Variables:
int pressure;                     //To store analog value

void setup(){

  Serial.begin(9600);       // Begin serial communication
  servo.attach(4);          //D2
  servo.write(0);

  delay(1000);
}

void loop(){
  pressure = analogRead(sensorOut);         //Read and store analog value from Force Sensitive Resistance
  Serial.println(pressure);                 //Print value
  pressure = map(pressure, 0, 1023, 0, 180);//Map value 0-1023 to 0-255 (PWM)
  servo.write(pressure);
  delay(100);
}

Download the "Control servo arm_FSR.ino" file and open it up in the Arduino IDE.

Then Create a new sketch and paste the code below in the Arduino IDE and hit Upload. You can tinker with it if you like based on the application, or just use it as it is.