RPI-UEXT allow Raspberry Pi to have access to different modules see original blog post we made about it: http://olimex.wordpress.com/2012/11/21/raspberry-pi-gpio-to-breadboard-and-uext-adapter/
MOD-IO2 allow RaspberryPi to control 2 relays and to read/write 7 additional GPIOs, including Analog inputs. On top of this MOD-IO2 is stackable and addressable so you can stack and connect to Raspberry Pi as many relays as you need for your project.
You have chance to win RPI-UEXT + CABLE26-pin + MOD-IO2 today if you answer correctly our quiz question!
Today at 17.00 o’clock our local Bulgarian time (GMT+2) we will post on Twitter our questions.
You have one hour to reply to our tweet with the correct answer.
At 18.00 o’clock we will count the correct answers and ask random.org to generate random number in range then announce the winner and ship the board by airmail in Monday.