LUA binding to GCS heartbeat

I’d like ardurover to HOLD if no heartbeat has been received from the GCS in 1 second. I think the best way to implement this is with a LUA script that checks the age of the heartbeat from the GCS. But I don’t believe this binding is currently available… Correct? @rmackay9 @tridge FYI. Next time you’re adding a new binding could you add this one??