Bojan Dragutinovic and I created the Ardusajzer in the MakerSpace using Arduino technology. This synthesizer has two voices and a two-step sequencer with 8 steps. The user can adjust the tempo to their preference and choose the pitch and duration for each step or skip it entirely. The Ardusajzer uses three Arduino boards, one for the tempo and two for the sequencers, and has three displays for easier use.
Project link: Github