Andy Merrill, 12, and Andrew Cluff, 13, both of Libertyville, spent Friday afternoon connecting LEDs to a breadboard and a Raspberry Pi credit-card sized computer.
It was the second meeting of a new program called "Teen Tinkers and Minecraft" at Cook Memorial Library in Libertyville, where students in grades seven through 12 learn how technological things work.
"We provide the gadgets, tools and electronic equipment," teen librarian Ellen Jennings said.
The program's focus will change each week, according to librarian Rob Eckmann, but it will center around electronics, computer software and hardware.
Several other teens attending Friday's session played Minecraft on an Xbox 360 and a large-screen projector.
"I'm going to bring a bunch of my friends next week -- there is nothing else like this in the community," Cluff said, "It's one thing to be excited about something yourself, but even more fun when you're with friends who understand the technology."