(CNN) A computer engineering graduate got his diploma and one heck of a story because the DIY electronic decoration on his graduation cap looked a bit like a bomb.

Can Cevik told CNN that police stopped him on Monday evening at a security entrance as he was walking into Florida International University's graduation ceremony.

They were suspicious of the gadget, which had a flashing, digital display that was connected to a 9-volt battery and electronic boards with red, black, yellow and green wires.

"They said 'hold on, we need to see what that is on your head,'" and told him to put the cap on the floor and step away, Cevik said. Then they had him empty his pockets and briefly took his cell phone.

"They were just basically trying to figure out what sort of a threat this could be, is it a bomb, that sort of thing," he said.