JOLT

This assistive device is a headband that is designed to keep myself awake during class and lectures. By tracking its orientation, the headband can sense when my head is out of alignment, indicating that I am nodding off and drifting to sleep. Once my head is too far off a straight forward-looking position, the headband will buzz and emit a high noise to wake me up, providing the jolt I need to pay attention in class or focus on my work.

In this video, I demonstrate the intended usage of the Jolt headband in a classroom environment. The device does not work due to hardware malfunctions and improper wiring, and so narration is accompanied to indicate what is supposed to occur. In this video, the headband is turned off. 

Transcript: 

In a resting position detailed as the headband facing straight forward, the headband remains silent. When rotational motion is detected, the headband will first buzz, then beep loudly, jolting the user awake. 

Process

I first wired the device using breadboards and the Arduino Uno, all parts I was most comfortable with, eventually moving to the Ardunio Micro Pro.  I initially believed the greatest struggle of the project would be getting the parts to fit within a headband and having it's weight supported by the headband. However, I found I greatly overestimated this issue and it was not a problem. 

The confined nature of the headband meant that any issues with the wiring once the headband was sewn would have to be fixed by taking apart the entire headband. There were multiple instances of parts breaking or the headband ceasing to work, at which I had to cut open the headband, fix the issue, and resew, which also took a lot of time. 

While the actual development, building, and coding of this project was relatively simple, much of my time was spent troubleshooting the issues that came up, which was mostly a result of the battery. Initially I incorrectly diagnosed the issue leading to some wasted time and resources on a solution, the transistor, that was not solving the problem of the mismatch between the 6V battery and the 5V accelerometer. I also experimented with two different voltage regulators in order to reduce the power. This was the biggest issue with my project that I ultimately could not fix. 

Discussion

Ultimately, I am unsatisfied with how the project came out as it was not functional, despite having a simple project. I am proud of a few aspects: the fact that I tried many solutions to many problems, I improved technical skills such as sewing and soldering, and my process in developing a device improved significantly from the last project. Instead of going straight to the final wiring, I took my time with understanding how each component worked by using more easily editable components such as the breadboards, which is something that I struggled with last project.  However, the battery issue was one that I could not overcome. It was during this time I truly felt the limitations of my understanding of circuits and wiring, as although I relied on sources from the internet, I did not completely understand why I was doing what I was doing to fix the problem. One problem that exacerbated the battery issue was that I had no way of reading the inputs from the accelerometer when it was not connected to my computer. In order to fix this for future development, I would wire an LCD screen in order to read these inputs and better be able to diagnose the issue.

Although I could not get a fully completed project for critique, I received a lot of great feedback that could help me improve the functionality for this device. One such feedback was the addition of a time delay so that if I needed to bend down and get something from my backpack, I could have some time to do so without the headband beeping. Another piece of feedback was making the values read from the headband relative rather than absolute, as in the accelerometer would first read 0 and every rotational change would be detected rather than its' absolute position. This would account for different ways I would wear the headband in different styles, whether I do so with my hair tied, resulting in a natural angle, or simply straight across my head. Both of these suggestions are great quality of life features I would implement in the future. In order to accomplish this, I would use the millis variable to count time once the head is out of position, and once ten+ seconds have passed, then the wake up mechanism will activate. I believe the relative positional change would use a variable that is the difference of the reading of the values from the accelerometer and it's initial value. One piece of feedback that I received that I disagree with was the inclusion of direction sensitive buzzers, or that the pancake motors would vibrate depending on which side I was leaning towards. I believe it is much more effective to have the whole headband shake at the temples in jolting me awake rather than having one buzzer, and there is not much added functionality in knowing what side I am leaning towards. 

Technical information

/*

Jolt

by Hannah Park

Rotational position is recorded using a 3 axis accelerometer.

Initially when the head rotates out of a certain range, two pancake vibration motors will turn on.

If the head continues to tilt further, a buzzer will activate.

All outputs will continue until the head is returned to a straight, forward facing position.

pin mapping

 pin | role  | details

 ------------------------------

 A0     input   X value for 3 axis accelerometer

 A1     input   Y value for 3 axis accelerometer

 A2     input   Z value for 3 axis accelerometer

 7      output  pancake motor

 8      output  active buzzer

*/

//actualizing variables

const int XPIN = A0;

const int YPIN = A1;

const int ZPIN = A2;

const int BUZZPINS = 8;

const int SCREAMPIN = 7;

int XVALUE;

int YVALUE;

int ZVALUE;

void setup() {

 pinMode(XPIN, INPUT);

 pinMode(YPIN, INPUT);

 pinMode(ZPIN, INPUT);

 pinMode(BUZZPINS, OUTPUT);

 pinMode(SCREAMPIN, OUTPUT);

 Serial.begin(9600);

}

void loop() {

 //reading the rotational position of headband and assigning it to a variable

 XVALUE = analogRead(XPIN);

 YVALUE = analogRead(YPIN);

 ZVALUE = analogRead(ZPIN);

 //printing out the values for testing purposes

 Serial.print(XVALUE);

 Serial.print(" ");   

 Serial.print(YVALUE);

 Serial.print(" ");

 Serial.println(ZVALUE);

//detecting if the head is slightly out of alignment to activate the motors: roughly a 20 degree angle away from a straight forward facing head. 

if (XVALUE < 390 || YVALUE > 380 || ZVALUE <300){

 digitalWrite(BUZZPINS, HIGH);

 Serial.print("buzz buzz");

}

else{

 digitalWrite(BUZZPINS, LOW);

}

//detecting if the head is very out of alignment to activate the buzzer: roughly a 45 degree angle away from a straight forward facing head. 

if (XVALUE < 370 || YVALUE >390 || ZVALUE <280){

 digitalWrite(SCREAMPIN, HIGH);

 delay(100);

 digitalWrite(SCREAMPIN, LOW);

 Serial.print("buzz buzz");

}

else{

 digitalWrite(SCREAMPIN, LOW);

}

}