Expand your Raspberry Pi with Arduino ports: 
As members of the maker community, we are always looking for creative ways to use hardware and software. This time, Patrick Lima and I decided we wanted to expand the Raspberry Pi’s ports using an Arduino board, so we could access more functionality and ports and add a layer of protection to the device. There are a lot of ways to use this setup, such as building a solar panel that follows the sun, a home weather station, joystick interaction, and more.
read more: Opensource.com brunoamuniz
Supporting Open Source.
Have you tried: Sailing in Africa ?