This paper focuses on the notable heightening of underrepresented students' engagement in STEM education through project-based learning CincySTEM iTEST projects. The projects, funded by an iTEST NSF grant, were designed and facilitated by teachers at a new STEM urban public high school serving low-income African-American students. Student engagement conceptualized as a psychological process involving affective and behavioral participation in classroom activities was evaluated through a mixed-methods approach. Findings indicate that affective and behavioral participation was significantly enhanced when project activities utilized digital devices in hands-on investigations of real-world project activities. Explanations for the success of CincySTEM iTEST projects are presented in the conclusion along with challenges for sustainability. [An erratum to this article is available at http://dx.doi.org/10.1007/s10956-016-9668-7.]