diff --git a/libraries/AP_Vehicle/AP_Vehicle.cpp b/libraries/AP_Vehicle/AP_Vehicle.cpp
index 77d183d30f..506a48f11d 100644
--- a/libraries/AP_Vehicle/AP_Vehicle.cpp
+++ b/libraries/AP_Vehicle/AP_Vehicle.cpp
@@ -13,6 +13,7 @@
 #include <AP_CheckFirmware/AP_CheckFirmware.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_CHIBIOS
 #include <AP_HAL_ChibiOS/sdcard.h>
+#include <AP_HAL_ChibiOS/hwdef/common/stm32_util.h>
 #endif
 
 #define SCHED_TASK(func, rate_hz, max_time_micros, prio) SCHED_TASK_CLASS(AP_Vehicle, &vehicle, func, rate_hz, max_time_micros, prio)
@@ -363,6 +364,9 @@ const AP_Scheduler::Task AP_Vehicle::scheduler_tasks[] = {
 #endif
 #if HAL_EFI_ENABLED
     SCHED_TASK_CLASS(AP_EFI,       &vehicle.efi,            update,                   50, 200, 250),
+#endif
+#if HAL_INS_ACCELCAL_ENABLED
+    SCHED_TASK(one_Hz_update,                                                         1, 100, 252),
 #endif
     SCHED_TASK(update_arming,          1,     50, 253),
 };
@@ -679,6 +683,36 @@ void AP_Vehicle::update_arming()
     AP::arming().update();
 }
 
+/*
+  one Hz checks common to all vehicles
+ */
+void AP_Vehicle::one_Hz_update(void)
+{
+    one_Hz_counter++;
+
+    /*
+      every 10s check if using a 2M firmware on a 1M board
+     */
+    if (one_Hz_counter % 10U == 0) {
+#if defined(BOARD_CHECK_F427_USE_1M) && (BOARD_FLASH_SIZE>1024)
+        if (!hal.util->get_soft_armed() && check_limit_flash_1M()) {
+            GCS_SEND_TEXT(MAV_SEVERITY_CRITICAL, BOARD_CHECK_F427_USE_1M);
+        }
+#endif
+    }
+
+    /*
+      every 30s check if using a 1M firmware on a 2M board
+     */
+    if (one_Hz_counter % 30U == 0) {
+#if defined(BOARD_CHECK_F427_USE_1M) && (BOARD_FLASH_SIZE<=1024)
+        if (!hal.util->get_soft_armed() && !check_limit_flash_1M()) {
+            GCS_SEND_TEXT(MAV_SEVERITY_INFO, BOARD_CHECK_F427_USE_2M);
+        }
+#endif
+    }
+}
+
 AP_Vehicle *AP_Vehicle::_singleton = nullptr;
 
 AP_Vehicle *AP_Vehicle::get_singleton()
diff --git a/libraries/AP_Vehicle/AP_Vehicle.h b/libraries/AP_Vehicle/AP_Vehicle.h
index 87e55daf22..a2245a79d8 100644
--- a/libraries/AP_Vehicle/AP_Vehicle.h
+++ b/libraries/AP_Vehicle/AP_Vehicle.h
@@ -445,6 +445,10 @@ private:
     // run notch update at either loop rate or 200Hz
     void update_dynamic_notch_at_specified_rate();
 
+    // decimation for 1Hz update
+    uint8_t one_Hz_counter;
+    void one_Hz_update();
+
     bool likely_flying;         // true if vehicle is probably flying
     uint32_t _last_flying_ms;   // time when likely_flying last went true
     uint32_t _last_notch_update_ms[HAL_INS_NUM_HARMONIC_NOTCH_FILTERS]; // last time update_dynamic_notch() was run
@@ -453,6 +457,7 @@ private:
 
     bool done_safety_init;
 
+
     uint32_t _last_internal_errors;  // backup of AP_InternalError::internal_errors bitmask
 
     AP_CustomRotations custom_rotations;