Driving electronic locks and LEDs at 24 V with Modbus Ethernet telemetry — the project looks straightforward until the channel count starts climbing.
Multiplexing is at the heart of the architecture. Rather than dedicating a full hardware path to every signal, the design optimizes resources with careful sequencing logic. The ATSAMD20J16B-MN orchestrates everything: output state management, multiplexing timing, control firmware, and network telemetry.
Modbus Ethernet turns the board into a networked node: it can receive commands and report its status within an existing IP-based control infrastructure. On the hardware side, separating 24 V power outputs, control logic, and the communication layer required real layout and grounding discipline.