Add an output device to a microcontroller board you've designed and program it to do something.
How to control something?
Power consumption
Microcontroller couldn't produce big amount of energy using its pins so if your output device (engine, motor, coil,...) consumes too much you should use independent power supply (or set of batteries). For my final project I made a locker based on stepper motor which needs driver and stabilizer.
I downloaded Eagle files of proto shield for Arduino from the official site and redesigned it. Firstly I deleted all unuseful things (to delete several items in the same time - define a group, choose delete tool and press Ctrl+Right Click on the group). I saved pins near the edges of the circuit board - the needed to insert shield to Galileo.
For motor driver I used ULN-UDN library, for voltage stabilizer - SM-Eagle library (Galileo 12V to 5V for the stepper motor). I took into account sensor (RFID module), motor driver, stabilizer and networking communication so final result looks like this:
I used power from VIN of Intel Galileo to supply a stepper motor with electricity. To limit the power I used 5V stabilizer, to control stepper motor I used driver which was included into package content with motor. To decrease number of wires I made reverse-engineering and soldered driver from the package.
Before cutting I checked designing rules in Eagle and found that my 0 Ohm resistor is too small so I decided to use wire to connect to electric routes. Board were cutted on FlexiCAM S2 150250:
The biggest problem was that I made 1 layer circuit where components should be connected from 2 different sides so there was a problem to solder components placed from the top.
After the soldering I tested almost every connection with tester and it saved me several hours later to debug my project. I programmed controller to open lock if the right RFID-card was read and close if the stop end pressed so it works like this:
