We designed and implemented a 10-week participatory design STEAM program for teens at Seattle Public Library. The program was held at Rainier Beach branch and eight teens ages 12 to 14 participated. Using KidsTeam UW as a model, we utilized techniques in codesign sessions including paper prototyping, creative narrative, big paper, stickies, and more. Design sessions culminated in participants building robots using Arduino. Data collected included analytical memos, recorded session video, and photographs. Lastly, we coded, analyzed, and synthesized to write design recommendations for Seattle Public Library to inform further iterations of participatory design and Arduino youth programs.