@homemaltster, when you say “Particle” do you have a specific device in mind (eg. Photono)? The SerialPort library provides low-level ring buffering which can’t be implemented as-is on Particle devices. However, it may be possible to use a FreeRTOS thread to create a reliable ring buffer using the low level FIFO buffer implemented in the DeviceOS. It may even be possible to implement without a thread since the Photon, for example, runs at a much faster clock than an ATMega328.