I have designed several different types of PCBs (printed circuit boards) for previous employers and personal use. This was probably the hardest project to complete, but the most rewarding.

I had to brush up on electrical theory and components, and learn an entire new software to make the schematics and board (Autodesk Eagle). Once I got comfortable, it felt like the sky was the limit. I wasn't able to find exactly the shield or boards that would fit my application perfectly, so I decided to build it instead.

The board seen here is a 2 relay shield that can snap right into an Arduino Mega. This, in addition to a built in 6 pin header for an Adafruit TC sensor, and Arduino's software environment allowed me to control the direction of a DC motor. This DC motor was attached to a carriage on a linear rail system, that inserted a cartridge heater into a component for thermal testing. I also used PLX-DAQ, which is a Microsoft Excel add-in with Arduino, which allows you to record and save data being read from the Arduino and TC. Flyback diodes were used across the relay terminals to ensure that the DC motor voltage spikes during a change of polarity wouldn't affect the rest of the circuitry.

In addition to the pin headers for jumper wires, there are also screw terminals to allow for easy terminations and routing using thicker gauge wire. It felt great to know every component had a proper place, and each wire could be securely fastened.