From 1e410301675bd2bc3ea1d9011fd9962777fba28a Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Wed, 12 Jul 2023 15:40:32 +1000
Subject: [PATCH] AP_AHRS: cope with AP_INERTIAL_SENSOR being 0

---
 libraries/AP_AHRS/AP_AHRS_Backend.h | 8 ++++++++
 libraries/AP_AHRS/AP_AHRS_config.h  | 4 ++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/libraries/AP_AHRS/AP_AHRS_Backend.h b/libraries/AP_AHRS/AP_AHRS_Backend.h
index 0fb02eae9b..ae71df9c0a 100644
--- a/libraries/AP_AHRS/AP_AHRS_Backend.h
+++ b/libraries/AP_AHRS/AP_AHRS_Backend.h
@@ -76,12 +76,20 @@ public:
 
     // get the index of the current primary accelerometer sensor
     virtual uint8_t get_primary_accel_index(void) const {
+#if AP_INERTIALSENSOR_ENABLED
         return AP::ins().get_primary_accel();
+#else
+        return 0;
+#endif
     }
 
     // get the index of the current primary gyro sensor
     virtual uint8_t get_primary_gyro_index(void) const {
+#if AP_INERTIALSENSOR_ENABLED
         return AP::ins().get_primary_gyro();
+#else
+        return 0;
+#endif
     }
 
     // Methods
diff --git a/libraries/AP_AHRS/AP_AHRS_config.h b/libraries/AP_AHRS/AP_AHRS_config.h
index 559d0403b0..7338a02787 100644
--- a/libraries/AP_AHRS/AP_AHRS_config.h
+++ b/libraries/AP_AHRS/AP_AHRS_config.h
@@ -21,11 +21,11 @@
 #endif
 
 #ifndef HAL_NAVEKF3_AVAILABLE
-#define HAL_NAVEKF3_AVAILABLE 1
+#define HAL_NAVEKF3_AVAILABLE AP_INERTIALSENSOR_ENABLED
 #endif
 
 #ifndef AP_AHRS_SIM_ENABLED
-#define AP_AHRS_SIM_ENABLED AP_SIM_ENABLED
+#define AP_AHRS_SIM_ENABLED AP_SIM_ENABLED && AP_INERTIALSENSOR_ENABLED
 #endif
 
 #ifndef AP_AHRS_POSITION_RESET_ENABLED