Loop pull sets interlock_latch_reset + interlock_latch within one 50 ms sample and both clear on reinsert; charge_pump_alive tracks the run and falls 0.45 s after the last charge-pump pulse (matches the measured R*C); estop follows it on both edges. Note that an interlock trip parks grblHAL in Door:0 until a cycle start.
docs/SAFETY.md documents the control board's laser safing chain as
reverse-engineered and bench-verified - parts, every net with its SoC pin,
Linux exposure and polarity, the logic, and the software layers ForgeFIRM
stacks on it - with docs/img/safety-chain.svg. Linked from the README.
BRINGUP: Next work item 11 records the interlock-latch finding (an open
loop never tripped the latch; the kernel now drives INTERLOCK_LATCH_RESET)
and the charge-pump watchdog readback, both code-complete and pinned,
bench validation on the next image.
ScottW514