Hyperterminal – Analysing Values of Different Wave types

SUMMARY

In this Brain wave series till now we have seen few real time applications on Brain Wave like controlling servo motor. Now presently I am planning to analyse the values of different wave types. So, I am just thinking to show the values on arduino serial monitor. I have just connected the arduino with my computer and trying to see the values on screen.

DESCRIPTION

Now, the Mindflex sensor sends the power FFT values of all the different wave types serially. So by receiving them on the arduino, we can send the values to the serial monitor of arduino. We have just connected the arduino to the PC and analyzing the values. First we have taken the values sent by Mindflex in the arduino board and then transferred them to the PC serially. We can see the values of the different wave types in the attached screenshot.

Fig. 1: Image showing FFT Values of Different Brain Waves

The sequence of the below string is:

“Signal strength, attention, meditation, delta, theta, low alpha, high alpha, low beta, high beta, low gamma, high gamma”

The limit of Signal Strength is 0 to 200. The lower the value, the higher is the signal strength. The average signal strength is in the range of 25 to 75. After that, the next two digits are attention and meditation. These values are 0 here as the signal strength is not 100 %. We have discussed this earlier that we can only get the attention and meditation values when the signal strength is 100 % and the numeric value coming from the MindFlex is 0. The attention and meditation values are sent by e meters of TGAM1 chip. Then there are power FFT values of different wave types. We have performed experiments using these different wave types earlier.

Please find attached below the block diagram on the connections we have done.

Fig. 2: Block Diagram of Brain Wave Analysis Device

Hardware: Please find the attached circuit diagram of the connections we need to do. We have taken a pin from T pin of the mindflex sensor and connected that pin to the Rx pin of our Arduino UNO. Also, we have shorted the ground of both the Sensor and UNO by a wire. Please take special care while soldering anything to the Mindflex sensor as pins are very close to each other. After establishing the connection with the Arduino UNO, we have simply connected the arduino with the PC using the Serial USB cable. This can also be done by using CP2102 and attaching the RX TX pin of the arduino with the CP2102 RX TX respectively.

Few points to Note:

The sensor usually gives the strength from 60 – 80% due to its orientation and the place where it’s located. Try to keep the metal sensor exactly above your left eye. I have also applied salt water at my forehead for better connectivity to the sensor. If you do not find it 100%, then it is normal. The signal strength also disrupts about how we solder the wire to the T pin.

Try to shield this wire and also make sure that the references probes are correctly connected. If you have any wire connected to the EEG pin of the sensor, please disconnect that wire as that will create much noise in the sensor values.

You can also make efforts to undertake the experiment and then share your feedback with us. Stay tuned for more experiments in the series.

Project Source Code

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//Program to 


// Arduino Brain Library - Brain SoftSerial Test
 
// Description: Grabs brain data from software serial on pin 10 and sends CSV out over the hardware serial
// More info: https://github.com/kitschpatrol/Arduino-Brain-Library
// Author: Eric Mika, 2014
 
#include 
#include 
 
// Set up the software serial port on pins 10 (RX) and 11 (TX). We'll only actually hook up pin 10.
SoftwareSerial softSerial(10, 11);
 
// Set up the brain reader, pass it the software serial object you want to listen on.
Brain brain(softSerial);
 
void setup() {
    // Start the software serial.
    softSerial.begin(9600);
    
    // Start the hardware serial. 
    Serial.begin(9600);
}
 
void loop() {
    // Expect packets about once per second.
    // The .readCSV() function returns a string (well, char*) listing the most recent brain data, in the following format:
    // "signal strength, attention, meditation, delta, theta, low alpha, high alpha, low beta, high beta, low gamma, high gamma"    
    if (brain.update()) {
        Serial.println(brain.readErrors());
        Serial.println(brain.readCSV());
    }
}
 
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