Regulating Power with the Arduino Uno

This is my first time using the Arduino Uno. My group is trying to make a smart heated jacket where the jacket would heat up at a certain temperature. We have temperature sensors located on the outside and inside of the jacket to calculate the average temperature on when the heating pads should be turned on. We are using heating pads that require 14V. How do we use data from the temperature sensors to regulate power to the heating pad?

Are the temperature sensors working? Are they working with the Arduino?

When the jacket is below temperature turn the power on, and when it's above the target temperature, turn it off.

The Arduino can't directly power much more than an LED, so you'll need a MOFTET or relay to control the power.

Technically, you don't need an Arduino (or software) to make a thermostat.

Have you calculated or experimented with battery requirements? Or are you carrying around a car battery in your backpack? :D

We have temperature sensors located on the outside...

Are you sure you need an outside sensor? Your home thermostat doesn't care what the outside temperature is...

You could also look at: https://www.element14.com/community/thread/2252/l/heating-control-circuit?displayFullThread=true You can control the power to the heating element by adjusting the duty cycle.

Yes the temperature sensors are connected with the Arduino Uno.

We're planning to use a drill battery on the bottom back side of the jacket.

We are using outside sensors for accuracy, the inside temperature sensors are not completely accurate. We have only a few temperature sensors located inside the jacket so you may have something in your jacket that causes heat at that part of the jacket but it doesn't represent your whole body.

Hi,

What temperature sensors are you using? What is the power rating of your heater, Watts or how much current does it draw, Amps. Are you zoning the heater areas, I could imagine some areas of a heated jacket getting warmer than others due to surrounding environment. The back of the jacket would need more energy due to the exposed surface area, the sleeve will not due to half of the arm facing the body.

Thanks.. Tom.... :)

We're using LilyPad temperature sensors. We're using heating pad from a car seat that requires 12V-14V, and we are going to sew it into the jacket.

We are having trouble figuring out a way to regulate power power from the heating pad

How many amps are being discussed? Switching a N-channel MOSFET with 3 to 5 PWM levels would be pretty easy. Look at AOI510 for example. http://www.digikey.com/product-detail/en/alpha-omega-semiconductor-inc/AOI510/785-1487-1-ND/3603498 Nice low Rds so you don't need to be concerned about cooling it much, and a logic level gate so an Arduino can drive it directly. (My old Jetta had a continuous setting knob for the heated seats, with end stops at 0 and 5, and detents at 1-2-3-4. My new Jetta has a push button with all off and 3 on-indicator lights).

Around 3 to 4 amps. We're undergraduates and this is the first project we are working on, can you please try to explain it in more detail.

Wire it up like this with the heating pad in place of the LEDs.
Can drive the MOSFET gate with PWM from one of these pins: 3,5,6,9,10,11

analogWrite (pwmPin, level);
with level from 0 to 255.