Auto-resume flight across chunk unload/reload

When the ship's chunk unloads the CC computer powers off and its redstone
outputs reset to 0, so on return the ship dropped and the pilot had to
re-ENGAGE every time. Flight state now survives the reboot:

- engaged.txt flag written while flying, cleared on pilot STOP.
- On boot, if engaged + profile present: drive the hover baseline
  immediately (closes the fall gap), then runStandby(true) re-enters the
  flight loop automatically with the persisted target -- no manual ENGAGE.
- runFly drives hover before its first sleep so no entry path leaves a
  0-output gap.
- Cleanup no longer lifts a PARKED ship: Ctrl+T out of standby holds hover
  only when engaged, else valves off.
- engaged.txt registered as per-ship state (gitignore, installer keep/reset,
  menu reset, build excludes).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitignore

@@ -9,6 +9,7 @@ files/*/calib.txt
 files/*/sides.txt
 files/*/target.txt
 files/*/settings.txt
+files/*/engaged.txt
 files/*/scan.txt
 files/*/pid_gains.txt
 files/*/.installed_*

README.md

@@ -63,7 +63,26 @@ Boot chain (autopilot): `startup.lua` → `ap boot` → `autopilot/main.lua`.
 Menu any time: `Ctrl+T`, then `ap`. (`stabilizeV2` remains as an alias.)
 
 Ship state lives on the computer only: `sides.txt`, `calib.txt`, `target.txt`,
-`settings.txt`. Reset it via menu `p` → `R`, or when re-running the installer.
+`settings.txt`, `engaged.txt`. Reset it via menu `p` → `R`, or when re-running
+the installer.
+
+## Surviving chunk unload / reload
+
+When you fly away and the ship's chunk unloads, the CC computer powers off and
+its redstone outputs reset to 0 — so on its own the ship would drop the moment
+you return. The autopilot handles this:
+
+- While flying it keeps an `engaged.txt` flag. On boot (`startup.lua` runs
+  automatically when the chunk reloads) it drives the hover baseline
+  **immediately**, then re-enters the flight loop on its own — no manual
+  ENGAGE, holding the same target it had.
+- A pilot **STOP** clears the flag, so a ship you deliberately stopped stays
+  stopped across reloads. **HOLD**/**LAND** keep flying, so they resume.
+
+There is still an unavoidable ~1–2 s gap while the computer boots; on this slow
+ship that is harmless. If the computer comes back *off* after a reload (some
+server setups), right-click it once — CC then runs `startup.lua` and the
+auto-resume takes over.
 
 ## Updating the code
 

build.sh

@@ -17,7 +17,7 @@ declare -A ROLE_SRC=(
 )
 
 # per-skip tilstand + utdaterte verktoey: shippes ALDRI (installeren rydder dem ogsaa)
-EXCLUDES=(calib.txt sides.txt target.txt settings.txt scan.txt pid_gains.txt
+EXCLUDES=(calib.txt sides.txt target.txt settings.txt engaged.txt scan.txt pid_gains.txt
           stabilize.lua diag.lua probe.lua scan.lua manifest)
 # rolle-spesifikt: cockpit-koden hoerer ikke hjemme paa autopilot-PCen
 declare -A ROLE_EXCLUDES=(

files/autopilot/autopilot/main.lua

@@ -97,6 +97,20 @@ local function profileComplete()
   return loadCalib().signMeasured == true
 end
 
+-- ENGASJERT-flagg: finnes filen <=> autopiloten FLYR aktivt (etter ENGAGE/FLY, foer STOP).
+-- Dette er kjernen i restart-overlevelsen: en chunk-unload slaar av datamaskinen, og reboot
+-- nullstiller redstone -> skipet ville falle. Ligger flagget der ved boot, gjenopptar vi flukten
+-- automatisk (og holder hover umiddelbart), i stedet for aa vente i standby paa manuell ENGAGE.
+local ENGAGED_FILE = "engaged.txt"
+local function setEngaged(on)
+  if on then
+    local f = fs.open(ENGAGED_FILE, "w"); f.write("1"); f.close()
+  elseif fs.exists(ENGAGED_FILE) then
+    fs.delete(ENGAGED_FILE)
+  end
+end
+local function isEngaged() return fs.exists(ENGAGED_FILE) end
+
 -- live brukerinnstillinger (justeres fra pilot-konsollen), persistert. Syntetiske noekler -> cfg.
 local SETTINGS_FILE = "settings.txt"
 local function saveSettings(t) local f = fs.open(SETTINGS_FILE, "w"); f.write(textutils.serialise(t)); f.close() end
@@ -713,6 +727,11 @@ local function runFly()
     print(""); print("[Enter]"); read(); return
   end
 
+  -- driv hover FOERST -- lukker fall-gapet (spesielt paa auto-resume etter reboot der
+  -- redstone kom tilbake paa 0) foer loopen og status-broadcasten kommer i gang.
+  driveValves(calib.uHoverFront, calib.uHoverRear)
+  setEngaged(true)   -- markér at vi FLYR -> overlever chunk-reload (auto-resume ved boot)
+
   local launchAlt = sensors.readAltitude() or 0
   local target = loadTarget() or (launchAlt + cfg.takeoffOffset)
   local est = Estimator.new(cfg)
@@ -739,6 +758,8 @@ local function runFly()
     elseif msg.cmd == "set" then applySetting(msg.key, msg.value, true)
     elseif msg.cmd == "stop" then stopReq = true end
   end
+  -- pilot-STOP er en eksplisitt "slutt aa fly" -> ryd engasjert-flagget saa en senere reload
+  -- IKKE gjenopptar av seg selv. (Ctrl+T beholder flagget: da vil du typisk fortsette senere.)
   -- vent ~dt sekunder MEN behandle innkommende kommandoer underveis (ikke-blokkerende styring)
   local function serve(secs)
     local timer = os.startTimer(secs)
@@ -823,7 +844,10 @@ local function runFly()
     })
 
     serve(cfg.dt)   -- vent dt + behandle pilot-kommandoer (erstatter sleep)
-    if stopReq then print("Pilot STOP -- holding hover, back to standby."); break end
+    if stopReq then
+      setEngaged(false)   -- eksplisitt stopp -> ikke auto-resume etter neste reload
+      print("Pilot STOP -- holding hover, back to standby."); break
+    end
   end
 end
 
@@ -898,7 +922,21 @@ local function awaitCmd(secs)
   end
 end
 
-local function runStandby()
+local function runStandby(autoResume)
+  link.open()
+  -- AUTO-RESUME: fl...y da chunken unloadet -> gjenoppta UMIDDELBART (ingen fall, ingen manuell
+  -- ENGAGE). Bare paa boot-inngangen; manuell "standby" fra menyen gjor det ikke.
+  if autoResume and isEngaged() and fs.exists(CALIB_FILE) then
+    term.clear(); term.setCursorPos(1, 1)
+    print("==== RESUMING FLIGHT ====")
+    print("Autopilot was flying before the chunk")
+    print("reloaded -- re-engaging automatically.")
+    print("(Pilot STOP to stop; it will NOT resume")
+    print(" after a stop.)")
+    sleep(0.6)
+    runFly()                                          -- blokkerer til STOP / Ctrl+T
+    local c = loadCalib(); driveValves(c.uHoverFront, c.uHoverRear)
+  end
   while true do
     -- re-proev modem hver runde: fanger et modem som plugges til mens vi staar i standby
     local hasModem = link.open()
@@ -939,6 +977,11 @@ end
 -- Foerste boot uten komplett profil -> tilby wizarden. Timeout -> standby, slik at en ubemannet
 -- reboot (chunk-reload) aldri blir staaende og vente paa tastetrykk.
 local function runBoot()
+  -- ALLER FOERST: fl...y vi da chunken unloadet? Driv hover UMIDDELBART saa skipet ikke rekker
+  -- aa falle mens vi tegner skjerm / venter. runStandby(true) gjenopptar selve reguleringen.
+  if isEngaged() and fs.exists(CALIB_FILE) then
+    local c = loadCalib(); driveValves(c.uHoverFront, c.uHoverRear)
+  end
   if not profileComplete() then
     term.clear(); term.setCursorPos(1, 1)
     print("==== AIRSHIP AUTOPILOT ====")
@@ -959,7 +1002,7 @@ local function runBoot()
       end
     end
   end
-  runStandby()
+  runStandby(true)   -- true = auto-resume flukt hvis vi fløy da chunken unloadet
 end
 
 -- ============================ PROFIL / MENY ============================
@@ -1015,7 +1058,7 @@ local function menu()
       term.clear(); term.setCursorPos(1, 1); showProfile()
       print("\nR = reset SHIP PROFILE (new ship), Enter = back"); local a = read():lower()
       if a == "r" then
-        for _, f in ipairs({ CALIB_FILE, SIDES_FILE, TARGET_FILE, SETTINGS_FILE }) do
+        for _, f in ipairs({ CALIB_FILE, SIDES_FILE, TARGET_FILE, SETTINGS_FILE, ENGAGED_FILE }) do
           if fs.exists(f) then fs.delete(f) end
         end
         print("Ship profile reset -- setup wizard on next boot."); print("[Enter]"); read()
@@ -1060,20 +1103,24 @@ local function runMode(mode, a2, a3)
   end)
   -- opprydding: aktive driv-modus -> hold hover (aldri etterlat drivende uten beskjed);
   -- monitor styrer ingenting (la utgangene staa).
+  local function holdHoverOut()
+    if fs.exists(CALIB_FILE) then
+      local c = loadCalib(); driveValves(c.uHoverFront, c.uHoverRear)   -- hold, ikke null (aldri stup)
+    else
+      allOff()
+    end
+  end
   if mode == "manual" or mode == "wiring" then
     allOff()
   elseif mode == "signtest" or mode == "setup" then
     -- Ctrl+T midt i sign-testen: luftbaaren -> hold hover (ALDRI frittfall); paa bakken -> alt av
-    if signtestAirborne then
-      local c = loadCalib(); driveValves(c.uHoverFront, c.uHoverRear)
-    else
-      allOff()
-    end
-  elseif mode == "cal" or mode == "fly" or mode == "observe" or mode == "standby" or mode == "boot" then
-    if fs.exists(CALIB_FILE) then
-      local c = loadCalib(); driveValves(c.uHoverFront, c.uHoverRear)   -- hold, ikke null (aldri stup)
-    else
-      allOff()   -- aldri floeyet under vaar kontroll -> skipet staar paa bakken; ikke varm brennere
+    if signtestAirborne then holdHoverOut() else allOff() end
+  elseif mode == "cal" or mode == "fly" or mode == "observe" then
+    holdHoverOut()   -- disse fl...yr aktivt -> hold hover ved avslutning
+  elseif mode == "boot" or mode == "standby" then
+    -- Ctrl+T ut av standby: hold hover KUN hvis vi faktisk fløy (engasjert). Et parkert skip
+    -- paa bakken skal IKKE begynne aa varme brennere og lette av seg selv.
+    if isEngaged() then holdHoverOut() else allOff()
     end
   end
   if not ok and err ~= "Terminated" then print("ERROR: " .. tostring(err)); print("[Enter]"); read() end

install.lua

@@ -20,7 +20,7 @@ local BASE  = "https://gt.zyon.no/Stian/airship-autopilot/raw/branch/main"
 local ROLES = { "autopilot", "cockpit" }
 
 -- per-skip tilstand: roeres aldri automatisk, men tilbys nullstilt ved install
-local STATE_FILES = { "sides.txt", "calib.txt", "target.txt", "settings.txt" }
+local STATE_FILES = { "sides.txt", "calib.txt", "target.txt", "settings.txt", "engaged.txt" }
 
 -- kjente filer fra eldre versjoner som ikke lenger hoerer til rollen (engangs-rydding;
 -- videre oppdateringer ryddes automatisk via installasjons-loggen .installed_<role>)