ford: show "Radar Not Detected" when the radar bus is silent

cereal/log.capnp

@@ -134,6 +134,7 @@ struct OnroadEvent @0xc4fa6047f024e718 {
     audioFeedback @97;
 
     soundsUnavailableDEPRECATED @47;
+    radarIsNotDetected @100;
   }
 }
 

opendbc_repo/opendbc/car/car.capnp

@@ -305,6 +305,7 @@ struct RadarData @0x888ad6581cf0aacb {
     radarFault @1 :Bool;
     wrongConfig @2 :Bool;
     radarUnavailableTemporary @3 :Bool;  # radar data is temporarily unavailable due to conditions the car sets
+    radarUnavailablePermanent @4 :Bool;  # radar data is permanently unavailable due to not having ACC
   }
 
   # similar to LiveTracks

opendbc_repo/opendbc/car/ford/radar_interface.py

@@ -25,6 +25,7 @@
 DELPHI_MRR_CLUSTER_THRESHOLD = 5  # meters, lateral distance and relative velocity are weighted
 
 STEER_ASSIST_DATA_MSGS = 0x3d7
+RADAR_ABSENT_ = 500 #Used to detect if the radar is absent for 5s and then set the radarUnavailablePermanent flag to True
 
 @dataclass
 class Cluster:
@@ -123,6 +124,8 @@ def __init__(self, CP, CP_SP):
     self.radar = DBC[CP.carFingerprint].get(Bus.radar)
     self.scan_index_invalid_cnt = 0
     self.radar_unavailable_cnt = 0
+    self.radar_perm_cnt = 0
+    self.radar_working = False
     self.prev_headerScanIndex = 0
     if CP.radarUnavailable:
       self.rcp = None
@@ -151,8 +154,16 @@ def update(self, can_strings):
     self.updated_messages.update(vls)
 
     if self.trigger_msg not in self.updated_messages:
+      if not self.radar_working:
+        self.radar_perm_cnt += 1
+        if self.radar_perm_cnt >= RADAR_ABSENT_:
+          ret = structs.RadarData()
+          ret.errors.radarUnavailablePermanent = True
+          return ret
       return None
     self.updated_messages.clear()
+    self.radar_working = True
+    self.radar_perm_cnt = 0
 
     ret = structs.RadarData()
     if not self.rcp.can_valid:

selfdrive/selfdrived/events.py

@@ -706,6 +706,11 @@ def invalid_lkas_setting_alert(CP: car.CarParams, CS: car.CarState, sm: messagin
     ET.NO_ENTRY: NoEntryAlert("Radar Temporarily Unavailable"),
   },
 
+  EventName.radarIsNotDetected: {
+    ET.PERMANENT: NormalPermanentAlert("Car may not have ACC"),
+    ET.NO_ENTRY: NoEntryAlert("Radar Is Not Detected"),
+  },
+
   # Every frame from the camera should be processed by the model. If modeld
   # is not processing frames fast enough they have to be dropped. This alert is
   # thrown when over 20% of frames are dropped.

selfdrive/selfdrived/selfdrived.py

@@ -380,6 +380,8 @@ def update_events(self, CS):
       self.events.add(EventName.canError)
     elif self.sm['radarState'].radarErrors.radarUnavailableTemporary:
       self.events.add(EventName.radarTempUnavailable)
+    elif self.sm['radarState'].radarErrors.radarUnavailablePermanent:
+      self.events.add(EventName.radarIsNotDetected)
     elif any(self.sm['radarState'].radarErrors.to_dict().values()):
       self.events.add(EventName.radarFault)
     if not self.sm.valid['pandaStates']: