Heating Pad Hand Warmer Blanket

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What are heating pads good for?

Heating Pad

There are a lot of great projects you can use heating pads in, ranging from warming gloves, slippers, a blanket, or anything you want to keep nice and warm. Got a beard mask you want to make toasty? Do beards need to be warmer? Not sure. Would it be a fun project? Definitely.

What parts should you consider getting for your project? You can go as simple as getting the appropriate power supply and a heating pad. One heating pad is rated for 5V, and draws about 600mA.

Part list for a basic setup:
Pick an appropriate power supply (there are tons of options available):
Wall Adapter Power Supply- TOL-08269
Heating Pad COM-11289 or COM-11288
Connector for your power supply (again, tons of options available): DC Barrel Jack Adapter - Male PRT-10287
Hook-up wire

If you want to add a form of logic or control to your circuit, such as interfacing with sensors, the easiest way is to add a microcontroller/development board to your project.

Please note: Make sure when using heatpads, not to leave unattended!

Here is a list of other tutorials you might find helpful while following this tutorial:
Basic Lilypad Tutorial
Beginning LilyPad Arduino

DIY Project Idea: Hand Warmer Blanket

A blanket project with two heating pads to keep your hands warm when you are on the computer/notebook/tablet/phone/playing chess/all other activities.

Part list:

There are a lot of parts on this list that can be exchanged for alternate parts, or that aren’t needed at all, depending on what type of setup you want.

If you do not want to sew or use conductive thread, exchange the Lilypad LEDs and Lilypad button for through-hole components and solder on a bigger protoboard instead.

You could use a 3.7 LiPo battery to power both the LilyPad USB board and the heating pads. Remember: You will still need a MOSFET, because having two heating pads will draw more current then the LilyPad pins can handle. This option is nice, since you can use the LilyPad to charge the LiPo battery when the heating pad isn’t in use. The draw back to using a 3.7v LiPo battery is that the heating pads won’t get as warm as they would with a 5v (or higher) power supply.

In this setup we use the LilyPad USB, because you won’t have to get an extra FTDI basic for an USB connection.


The first step is to select your fabric. When picking a fabric, you want to consider the following:

  • Is the pattern on the fabric going to work, or look out of place? If you are going Snuggie style, will you need to add extra fabric for the arms?
  • On what level of awesome is the fabric you are selecting? Meaning, how fast are you going to get sick of looking at it?
  • Is the fabric thick, cozy, and going to keep the rest of your body warm? Sheer, light fabrics don’t help to keep you warm during the winter months.

In the video below, you’ll see that you can get as weird as you want when customizing your blanket:

For the example in the video, extra fabric and button snaps were sewn on the back of the blanket for easy removal for washing.

Heating pad blanket with sewing snaps

If you don’t have a sewing machine, or don’t want to sew, you can do a No-Sew blanket and be creative when adding a pouch that holds your heating pads and circuit. No-Sew blanket tutorials


Here is a diagram of the circuit setup:


Please note: As you can see, the LilyPad LEDs and Lilypad Button were sewn into the fabric, but you can easily switch these for normal, through-hole LEDs, and a button soldered on a protoboard with the other soldered components.

Important! Make sure to solder hook-up wire to your heating pad connections. DO NOT try to use conductive thread to connect the two heating pads.

Example Code


 Heating Pad Hand Warmer Blanket Code Example
  SparkFun Electronics, Pamela, 1/24/2013
  Beerware License

  Hardware Connections:
  -led1 = D9;
  -led2 = D10;
  -led3 = D11;
  -button = D2;
  -Mofset = D3;

  Hit the switch to power, hit the button to adjust how warm the heating elements get, and three LEDs will indicate low, medium, and high levels. 

int btnPin = 2;
boolean btnPressed = false;
int fetPin = 3;
int led1 = 9;
int led2 = 10;
int led3 = 11;
int mode;

void setup() {                
  // initialize the digital pin as an output.
  pinMode(btnPin, INPUT);  
  pinMode(fetPin, OUTPUT);  
  pinMode(led1, OUTPUT);  
  pinMode(led2, OUTPUT);  
  pinMode(led3, OUTPUT);  

// the loop routine runs over and over again forever:
void loop() {
  //Increment mode on depress, unless mode = 3, then reset to 0
  if (btnPressed && digitalRead(btnPin) == LOW)
    mode = mode == 3 ? 0 : mode + 1;
  //Assign button state
  btnPressed = digitalRead(btnPin);
  switch (mode)
    case 0:
      analogWrite(fetPin, 0); //off
      digitalWrite(led1, LOW);
      digitalWrite(led2, LOW);
      digitalWrite(led3, LOW);
    case 1:
      analogWrite(fetPin, 85); //33% duty cycle
      digitalWrite(led1, HIGH);
      digitalWrite(led2, LOW);
      digitalWrite(led3, LOW);
    case 2:
      analogWrite(fetPin, 170); //66% duty cycle
      digitalWrite(led1, HIGH);
      digitalWrite(led2, HIGH);
      digitalWrite(led3, LOW);
    case 3:
      analogWrite(fetPin, 255); //100% duty cycle
      digitalWrite(led1, HIGH);
      digitalWrite(led2, HIGH);
      digitalWrite(led3, HIGH);

There you go! As with any DIY project, you should always customize and tweak what you want for maximum awesomeness.

If you liked this project, we recommend checking out the following tutorials:
Twinkling Fairy Wings