Microcontrollers are low-cost and energy efficient programmable integrated circuits, they are used in a lot of common electronic devices but are quite difficult to program because of very limited resources. Being particularly used for embedded system, they interact a lot with their environment, and should react quickly to external stimuli. In this paper, we study different models of concurrency for programming microcontrollers using a virtual machine approach for safety as well as a higher-level model of programming. We then propose OCaLustre, the prototype of a synchronous extension to OCaml suitable for concurrent programming on microcontrollers.