Introduction: Hot Pocket Introduction

In 2018 alone, eighty thousand people died from flu-like symptoms with the most common aggravator of the flu and common cold causing a weakened immune system. The main focus of our project was to produce a jacket that keeps a wearer’s body temperature warm and reduce any physical risks. Focusing on producing a smart jacket that will monitor and adjust the temperature as needed. Also adding the ability to lessen or heighten the intensity of the heat while also providing an emergency stop for no heating of the jacket to quickly cool the wearer. The safety aspects also include not running while if the weather is not permitting (i.e. the jacket will not turn on if the temp of the wearer is over a safe limit).

Step 1: Materials

Step 2: How the Project Works

By using temperature sensors, we gather information regarding the wearer's body temperature and with that information, we can actively adjust the voltage going to the jackets heated pads. This changes the temperature of the heating element and adjusts the temperature very effectively. The wiring all works with the limitations with the Itsy Bitsy with special control over the large voltage that the product requires.

Step 3: Prototype 1

This prototype had the intention of testing all of the parts of the project. The voltage control of the heating elements, temperature readings, a test run of the code. All of the parts that are tested here will be put together slowly onto the jacket that we used.

Steps in making the prototype:

  1. Add Node MCU to the breadboard for testing objects and sensors
  2. Plug in Node MCU to MicroUSB for testing code
  3. Connect a section of wire from the heating element to pin 9
  4. Connect the 5v and GND to positive and negative respectively
  5. Connect the temperature sensor to the 5v, SCL, SDA, and ground
  6. Connect the potentiometer to the A5 pin and 5v lane
  7. Connect the button to the A0 pin and 5v lane

Step 4: Physical Prototype 2

After prototype 1, we were able to fully test the functionality of the product. So the next step was continuing on testing the heating pads because of their instability and then after that putting the heating pads into the jacket. The major thing about testing the heating pad was the voltage and what type of batteries to use. For this, we had to purchase rechargeable 9 volts that allowed for the jacket to be reused time and time again. We also need to put in all the wires for the different sensors and interactive functions. that done after planning out where the location of the wires and other sensors would be based on the drawing.


  1. Sew temperature sensor onto the inside of the jacket.
  2. Have wires extending and running down close to the pocket area.
  3. Combine ground and power for the button which is above the location of the temperature sensor with the VIN on the temperature sensor.
  4. Find a location to attach a potentiometer to the jacket and create a hole for the potentiometer.
  5. Run ground, power, and signal wire from the potentiometer to an area close to the pocket.
  6. Solder on all loose wires to their correct pin inputs on the itsy bitsy.

Step 5: Finishing Touches Prototype 3

All of the functionality and location for the jackets were made and all the functions worked so the final step was putting all the wires inside the jacket and adding the finishing touches such as 3D prints for the potentiometer and holder for the batteries and a container for the itsy bitsy. This step slowly required putting all of the different objects that were outside of the jacket in between the two layers of the jacket and sewing everything up


  1. Use alligator clips to attach the wiring to the jacket and remove the portion of the clips that allow for no interference from bumps against walls or pressure put onto the contact points.
  2. Attach heating pads to the jackets so that the pads are not covering any of the jacket material and have clearance to the user
  3. Sew potentiometer and screw in hex nut to the outside of the jacket.
  4. Fix wiring to be routed through to the inside of the pocket.
  5. In the inside of the pocket, add a holder for three 9-volt batteries with connections using a split 9-volt buckle.
  6. Cover any remaining holes with electrical tape and stitching.

Step 6: Code


The jacket required for the code has to be both be safe for the wear and also apply the appropriate voltage to the heating pads so that the jacket is able to adjust the temperature internally. To do this there are four key functions.

The first function is the emergency stop for the safety of the weird, acting as the last step of safety in cases of emergency or negligence. If the user has a temperature that reads greater than 85 degrees Fahrenheit, which would cause a massive increase in the body temperature of the user and does not turn off the jacket, the jacket will turn off immediately and shut all the voltage to the heating pads

The next function is the potentiometer having slight adjustments to increase or decrease the heat settings of the user. If the user would prefer the heating pads to be more active, they can increase the potentiometer knob to the left to increase the voltage from the itsy bitsy and vice versa if they wanted to be cooler.

The third and function is the emergency stop button if at any point the user is uncomfortable and acts as an extra layer of safety for the user. if at any point there is damage from the outside world to the jacket the user can immediately use the emergency stop to causes no harm to themselves from any of the jackets elements. The emergency stop also functions in case the user themselves feels uncomfortable with the amount of heat even if it isn't a danger to themselves or others.

The final and most crucial aspect of this project is the function that adjusts the voltage to the heating elements, there for adjusting the temperature inside the jacket. Because the jacket is very well-insulated by testing the heating pads internally prior to finishing up the project we were able to assign certain voltages to certain temperatures for the user to feel. Lower voltages almost always meant that there would be less keep going to the user's body while the higher voltages made it hotter. The function acts as an exponential growth system, where the temperature is significantly increased by minor adjustments in the voltage.

With all of these systems in place, it allows for the user to safely and comfortably use the jacket in everyday life. These set of functions work as the backbone for our project and allow for any part of the jacket to work as intended.

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First Time Author