Step 1: Gather Your Materials

Materials:

Arduino Uno

(2x) 6"x 6" 1/4" Aluminum Plates

Several Peltier Therm o-electric Cooling Modules.

(4x) 2" long 3/8" hex head bolts

(4x) 3/8" nuts

(4x) 3/8" lock washers

1k resistor

SRD 05VDC SL C relay switch

12 volt power source for the peitier modules

power source for the arduino uno

Breadboard

4 prong button

Tools:

Soldering Iron

Lead Solder

Needle Nose Pliers

Wire Strippers

Solid Gauge Wire

Multi-meter

Band-aids

Antibiotic Ointment

Patience

Step 2: Test Your Thermoelectric Peltier Modules

Make sure to purchase several peltier modules because there is a chance 1 or 2 of them will not work. The red wire is your positive wire, and the black one is your ground wire. I think I ended up ordering about 10 of the peltier modules because it was such a good deal through Amazon.

Step 3: Measure and Drill Your Aluminum Plates

Measure and mark your aluminum plates with a sharpie in order to get them ready for drill press. Even though aluminum is a very soft metal, make sure you use some kind of oil lubricant to keep your drill bit from overheating or even messing up the size of your holes. For convenience I would put one plate on top of the other and drill through both plates simultaneously to ensure that your holes line up.

Step 4: Wiring Your Breadboard

When wiring up my bread board I ended up using a simple arduino program from the program library called Debounce that turned the relay on and off when I pressed the button. Starting with the button I ran the power wire (yellow wire) from the 5 volt port on the arduino to the left prong on the button. The black wire (your ground wire) should run from the ground port just underneath the 5 volt port over to the ground rail of your breadboard. The right prong of your button. You should have your 1k resistor going from the right prong of your button to the ground rail of your breadboard. Run a wire from port 4 to the left prong of your relay. The middle prong should have the positive wire of your peltier module soldered to it and the prong next to it,( the right prong) should run back to your ground rail and connect to the other side of your 1k resistor.

Step 5: Assembling Your Coaster

When you get ready to assemble your coaster, make sure you face the cold side of your peltier module to the top of the coaster other wise you will just end up with a hot plate. When you tighten the bolts, make sure you dont tighten them too tightly. Just make them snug.

Step 6: Please Use Safety

It is so easy, to take safety for granted. It it only take a second for an accident to happen. So please be extremely careful with your soldering iron.