Show HN: Formally verified FPGA watchdog for AM broadcast in unmanned tunnels
Summary
Show HN presents a 12-channel AM radio system built on Red Pitaya FPGA with a formally verified watchdog timer. The design uses a Rust/JS MVC GUI, a TCP/SCPI bridge to the FPGA, and a formal verification workflow (SymbiYosys + Z3) to prove 14 safety properties; the watchdog kills RF output if the GUI heartbeat is lost, requiring operator reset to resume transmission. The project emphasizes safety in unattended tunnel environments and documents architecture, verification, testing, and deployment steps.