diff --git a/Tools/AP_Periph/AP_Periph.cpp b/Tools/AP_Periph/AP_Periph.cpp
index 75a6e73977..74164b7f6d 100644
--- a/Tools/AP_Periph/AP_Periph.cpp
+++ b/Tools/AP_Periph/AP_Periph.cpp
@@ -217,6 +217,28 @@ static void update_rainbow()
 #endif
 
 
+#if CONFIG_HAL_BOARD == HAL_BOARD_CHIBIOS && CH_DBG_ENABLE_STACK_CHECK == TRUE
+void AP_Periph_FW::show_stack_free()
+{
+    const uint32_t isr_stack_size = uint32_t((const uint8_t *)&__main_stack_end__ - (const uint8_t *)&__main_stack_base__);
+    can_printf("ISR %u/%u", stack_free(&__main_stack_base__), isr_stack_size);
+
+    for (thread_t *tp = chRegFirstThread(); tp; tp = chRegNextThread(tp)) {
+        uint32_t total_stack;
+        if (tp->wabase == (void*)&__main_thread_stack_base__) {
+            // main thread has its stack separated from the thread context
+            total_stack = uint32_t((const uint8_t *)&__main_thread_stack_end__ - (const uint8_t *)&__main_thread_stack_base__);
+        } else {
+            // all other threads have their thread context pointer
+            // above the stack top
+            total_stack = uint32_t(tp) - uint32_t(tp->wabase);
+        }
+        can_printf("%s STACK=%u/%u\n", tp->name, stack_free(tp->wabase), total_stack);
+    }
+}
+#endif
+
+
 
 void AP_Periph_FW::update()
 {
@@ -242,13 +264,28 @@ void AP_Periph_FW::update()
         hal.uartA->printf("RNG %u %ucm\n", rangefinder.num_sensors(), rangefinder.distance_cm_orient(ROTATION_NONE));
 #endif
         hal.scheduler->delay(1);
-        show_stack_usage();
 #endif
 #ifdef HAL_PERIPH_NEOPIXEL_COUNT
         hal.rcout->set_serial_led_num_LEDs(HAL_PERIPH_NEOPIXEL_CHAN, HAL_PERIPH_NEOPIXEL_COUNT, AP_HAL::RCOutput::MODE_NEOPIXEL);
 #endif
     }
 
+    static uint32_t last_error_ms;
+    const auto &ierr = AP::internalerror();
+    if (now - last_error_ms > 5000 && ierr.errors()) {
+        // display internal errors as DEBUG every 5s
+        last_error_ms = now;
+        can_printf("IERR 0x%x %u", ierr.errors(), ierr.last_error_line());
+    }
+
+#if CONFIG_HAL_BOARD == HAL_BOARD_CHIBIOS && CH_DBG_ENABLE_STACK_CHECK == TRUE
+    static uint32_t last_debug_ms;
+    if (g.debug==1 && now - last_debug_ms > 5000) {
+        last_debug_ms = now;
+        show_stack_free();
+    }
+#endif
+    
 #ifdef HAL_PERIPH_ENABLE_BATTERY
     if (now - battery.last_read_ms >= 100) {
         // update battery at 10Hz
diff --git a/Tools/AP_Periph/AP_Periph.h b/Tools/AP_Periph/AP_Periph.h
index c14b90afab..ebf14bff76 100644
--- a/Tools/AP_Periph/AP_Periph.h
+++ b/Tools/AP_Periph/AP_Periph.h
@@ -132,6 +132,9 @@ public:
     uint32_t last_gps_update_ms;
     uint32_t last_baro_update_ms;
     uint32_t last_airspeed_update_ms;
+
+    // show stack as DEBUG msgs
+    void show_stack_free();
 };
 
 extern AP_Periph_FW periph;
diff --git a/Tools/AP_Periph/Parameters.cpp b/Tools/AP_Periph/Parameters.cpp
index 7f5ca85258..1003277e53 100644
--- a/Tools/AP_Periph/Parameters.cpp
+++ b/Tools/AP_Periph/Parameters.cpp
@@ -38,7 +38,9 @@ const AP_Param::Info AP_Periph_FW::var_info[] = {
     // trigger bootloader flash
     GSCALAR(flash_bootloader,     "FLASH_BOOTLOADER", 0),
 #endif
-    
+
+    GSCALAR(debug, "DEBUG", 0),
+
 #ifdef HAL_PERIPH_ENABLE_BUZZER
     GSCALAR(buzz_volume,     "BUZZER_VOLUME", 100),
 #endif
@@ -104,7 +106,7 @@ const AP_Param::Info AP_Periph_FW::var_info[] = {
 #ifdef HAL_PERIPH_ENABLE_HWESC
     GSCALAR(esc_number, "ESC_NUMBER", 0),
 #endif
-    
+
     AP_VAREND
 };
 
diff --git a/Tools/AP_Periph/Parameters.h b/Tools/AP_Periph/Parameters.h
index 88c1730cfa..ae1ee90bc7 100644
--- a/Tools/AP_Periph/Parameters.h
+++ b/Tools/AP_Periph/Parameters.h
@@ -29,6 +29,7 @@ public:
         k_param_baro_enable,
         k_param_esc_number,
         k_param_battery,
+        k_param_debug,
     };
 
     AP_Int16 format_version;
@@ -63,7 +64,9 @@ public:
 #ifdef HAL_PERIPH_ENABLE_HWESC
     AP_Int8 esc_number;
 #endif
-    
+
+    AP_Int8 debug;
+
     Parameters() {}
 };