As we did in previous sketches, we are going to use EEG data to control the speed of a DC motor by using PWM. But this time, we will remove the USB cable and use the Bluetooth connection to transfer the EEG data from Processing to Arduino.

 

Here is the Arduino code

/*

Developed by Alis Design, March 2015
Revisited November 2017
www.alis.design

based on the sketch developed by
Guilherme “guibot” Martins
Control your motors with L293D
Sep, 2008
http://letsmakerobots.com/node/2074

*/

#include <SoftwareSerial.h>// import the serial library

SoftwareSerial B(4, 5); // RX, TX

int motor_left[] = {2, 3};
int motor_right[] = {7, 8};
int motor_speed = 9;

int BluetoothData; // the data given from Computer

void setup() {
B.begin(9600);
Serial.begin(57600);

// Setup motors
for(int i = 0; i < 2; i++){
pinMode(motor_left[i], OUTPUT);
pinMode(motor_right[i], OUTPUT);
}
pinMode(motor_speed,OUTPUT);

}

void loop() {
if (B.available()){
BluetoothData=B.read();
if(BluetoothData>50){
analogWrite(motor_speed, BluetoothData);
drive_forward();
}
else{
motor_stop();
}
}
Serial.println(BluetoothData);
}


//================================= drive

void motor_stop(){
digitalWrite(motor_left[0], LOW);
digitalWrite(motor_left[1], LOW);

digitalWrite(motor_right[0], LOW);
digitalWrite(motor_right[1], LOW);
delay(25);
}

void drive_forward(){
digitalWrite(motor_left[0], HIGH);
digitalWrite(motor_left[1], LOW);

digitalWrite(motor_right[0], HIGH);
digitalWrite(motor_right[1], LOW);
}

void drive_backward(){
digitalWrite(motor_left[0], LOW);
digitalWrite(motor_left[1], HIGH);

digitalWrite(motor_right[0], LOW);
digitalWrite(motor_right[1], HIGH);
}

void turn_left(){
digitalWrite(motor_left[0], LOW);
digitalWrite(motor_left[1], HIGH);

digitalWrite(motor_right[0], HIGH);
digitalWrite(motor_right[1], LOW);
}

void turn_right(){
digitalWrite(motor_left[0], HIGH);
digitalWrite(motor_left[1], LOW);

digitalWrite(motor_right[0], LOW);
digitalWrite(motor_right[1], HIGH);
}

 

and the Processing code

/*
 
 Developed by Alis Design, March 2015
 Revisited November 2017
 www.alis.design
 
 based on the sketch developed by
 Guilherme “guibot” Martins
 Control your motors with L293D
 Sep, 2008
 http://letsmakerobots.com/node/2074
 
 based on the library developed by
 Andreas Borg
 http://crea.tion.to/
 */


//================================= neurosky

import neurosky.*;
import org.json.*;
ThinkGearSocket neuroSocket;
int attention, meditation, delta, theta, low_alpha, high_alpha, low_beta, high_beta, low_gamma, mid_gamma, sig, blinkStrength;

//================================= arduino and bluetooth

import processing.serial.*;
Serial port;
int[] numbers = new int[10];
int BluetoothData;

//================================= smoothing 

int numReadings = 300;

int[] readings=new int[numReadings];      // the readings from the analog input
int index = 0;                            // the index of the current reading
int total = 0;                            // the running total
int average = 0;                          // the average


//================================= font

PFont f;

//================================= init

void setup() {
  size(500, 500);

  for (int thisReading = 0; thisReading < numReadings; thisReading++)
    readings[thisReading] = 0;

  // initialize the font object
  f = createFont("Arial", 16, true); // Arial, 16 point, anti-aliasing on

  // use the serial device
  println(Serial.list()); 
  port = new Serial(this, "/dev/tty.HC-06-DevB", 9600);  

  // initialize the headset
  ThinkGearSocket neuroSocket = new ThinkGearSocket(this);
  try {
    neuroSocket.start();
  } 
  catch (Exception e) {
    println("Is ThinkGear running??");
  }
}

void clearBackground() {
  background(40);
}


//================================= loop
void draw() {
  clearBackground();
  textFont(f, 180);                          //  Specify font to be used
  fill(255);                                 //  Specify font color 
  text(BluetoothData, width/2, height/2);    //  Display Text
  textAlign(CENTER);


  total= total - readings[index];            // subtract the last reading:      
  readings[index] = attention;               // read from the sensor: 
  total= total + readings[index];            // add the reading to the total:
  index = index + 1;                         // advance to the next position in the array:  

  // if we're at the end of the array...
  if (index >= numReadings)              
    // ...wrap around to the beginning: 
    index = 0;                           

  average = total / numReadings;             // calculate the average:
  BluetoothData = floor(average * 2.55);     // we are mapping the attention value (0-100) to (0-255)
  port.write(BluetoothData); 
  delay(1);                                  // delay in between reads for stability
}

//================================= neurosky functions

void poorSignalEvent(int sigLevel) {
  sig=sigLevel;
}

void attentionEvent(int attentionLevel) {
  attention = attentionLevel;
}

void meditationEvent(int meditationLevel) {
  meditation = meditationLevel;
}

void blinkEvent(int blinkStrengthLevel) {
  blinkStrength = blinkStrengthLevel;
}

void eegEvent(int deltaLevel, int thetaLevel, int low_alphaLevel, int high_alphaLevel, int low_betaLevel, int high_betaLevel, int low_gammaLevel, int mid_gammaLevel) {
  delta = deltaLevel;
  theta = thetaLevel;
  low_alpha = low_alphaLevel;
  high_alpha = high_alphaLevel;
  low_beta = low_betaLevel;
  high_beta = high_betaLevel;
  low_gamma = low_gammaLevel;
  mid_gamma = mid_gammaLevel;
}

void rawEvent(int[] rawArray) {
}  

void stop() {
  neuroSocket.stop();
  super.stop();
}

 

 

 

In Processing, before sending the Attention Values to Arduino, we are smoothing the values so that the data that will be transferred to drive the DC motor will be cleared out from spikes that may affect the efficiency of the system.

https://vimeo.com/241054033

That is all for this sketch and we are going to proceed with creating some tangible devices using the information we gathered through these sketches.

Stay tuned…