fix(dronecan): count stall-rail trips in esc.Status error_count

Inc/faults.h

@@ -74,4 +74,34 @@ void faultDesyncEpisodeTick1kHz(void);
 /* True while a post-desync coast is mandatory (caller must not re-start). */
 uint8_t faultDesyncRestartHoldoffActive(void);
 
+/*
+ * Monotonic since-boot count of stall-rail trips on an ESTABLISHED run - the
+ * same zero_crosses > 100 gate the episode charge uses, so the many legitimate
+ * kicks a heavy prop needs at low throttle are not counted as errors.
+ *
+ * volatile: read from the main loop (telemetry) while the grind rail that
+ * forces this trip runs in tenKhzRoutine (ISR context).
+ */
+extern volatile uint32_t fault_stall_trips;
+
+/*
+ * Total hard-error events since boot, for uavcan.equipment.esc.Status
+ * error_count ("errors since start-up").
+ *
+ * Sums the two PRIMITIVE run-killers, which are mutually exclusive:
+ *   - desync_happened   : the jump-desync check in runtimeProcessDesyncCheck
+ *   - fault_stall_trips : the INTERVAL_TIMER stall rail
+ *
+ * Deliberately NOT additional addends, because each already funnels into the
+ * stall rail and would double-count one physical failure:
+ *   - blind-grind rail (faultDesyncEpisodeTick1kHz) kicks INTERVAL_TIMER to
+ *     46000 so the stall rail is guaranteed to trip on the next main pass
+ *   - blind-step / miss-bucket limit (bemf_zc.c) hands off the same way
+ *   - the episode-rail latch is a CONSEQUENCE of accumulating the above, and
+ *     is a state (ESC_FAULT_STUCK), not an independent event
+ * Attribution between those sub-causes belongs in the AM32-reserved FlexDebug
+ * payload, not in this scalar.
+ */
+uint32_t faultErrorCount(void);
+
 #endif /* FAULTS_H_ */

Mcu/SITL/tests/test_dronecan.py

@@ -35,6 +35,7 @@ def test_dronecan_throttle_and_esc_status(sitl_can_factory, state_stream, mcast_
     def on_esc(e):
         status['rpm'] = e.message.rpm
         status['voltage'] = e.message.voltage
+        status['errors'] = e.message.error_count
         status['count'] = status.get('count', 0) + 1
 
     node.add_handler(dronecan.uavcan.equipment.esc.Status, on_esc)
@@ -59,6 +60,12 @@ def on_esc(e):
         assert 3500 <= status.get('rpm', -1) <= 6500, status
         assert 15 < status.get('voltage', 0) < 18, status
         assert status.get('count', 0) >= 3, 'too few esc.Status: %s' % status
+        # error_count aggregates hard-error events (jump desync + stall rail).
+        # An honest spool-up to a steady 4-6k rpm must report none: the stall
+        # rail is gated on zero_crosses > 100 precisely so the kicks a normal
+        # start needs are not counted as errors.
+        assert status.get('errors', -1) == 0, \
+            'healthy run reported error_count=%s' % status.get('errors')
     finally:
         # stop motor
         for _ in range(10):

Src/DroneCAN/DroneCAN.c

@@ -14,6 +14,7 @@
 #	include "signal.h"
 #	include "version.h"
 #	include "eeprom.h"
+#	include "faults.h"
 #	include <stdarg.h>
 #	include <stdio.h>
 #	include <string.h>
@@ -107,7 +108,6 @@ extern volatile char armed;
 extern volatile uint32_t commutation_interval;
 extern uint8_t auto_advance_level;
 extern uint16_t low_cell_volt_cutoff;
-extern uint32_t desync_happened;
 
 static uint16_t last_can_input;
 static uint64_t last_heartbeat_us;
@@ -1006,8 +1006,11 @@ static void send_ESCStatus(void)
 	struct uavcan_equipment_esc_Status pkt;
 	uint8_t buffer[UAVCAN_EQUIPMENT_ESC_STATUS_MAX_SIZE];
 
-	// make up some synthetic status data
-	pkt.error_count = desync_happened; // fill desync count here
+	/* Hard-error events since boot. Was desync_happened alone, which missed
+	 * every run killed by the stall rail (and so also the blind-grind and
+	 * blind/miss-limit paths that funnel into it) - a grinding motor
+	 * reported error_count 0. See faultErrorCount(). */
+	pkt.error_count = faultErrorCount();
 	pkt.voltage = battery_voltage * 0.01;
 
 	pkt.current = (current.sum / (float)current.count) * 0.01;

Src/faults.c

@@ -27,6 +27,14 @@ extern volatile uint16_t zero_input_count;
 extern volatile uint32_t dma_buffer[64];
 extern void resetInputCaptureTimer(void);
 
+/* See the comments on the declarations in faults.h. */
+volatile uint32_t fault_stall_trips = 0;
+
+uint32_t faultErrorCount(void)
+{
+	return desync_happened + fault_stall_trips;
+}
+
 uint8_t faultHandleStuckRotorIfNeeded(void)
 {
 #ifndef BRUSHED_MODE
@@ -327,6 +335,12 @@ void faultHandleBemfIntervalStall(void)
 		// this rail is guaranteed to run next pass): blind stepping only
 		// arms at zero_crosses >= 100, so those episodes always charge.
 		if (zero_crosses > 100) {
+			/* Established run died here. This is the ONLY place the
+			 * stall rail is counted, and it is the aggregation point
+			 * for the grind rail and the blind/miss-limit handoff,
+			 * both of which reach the loop through this trip - see
+			 * faultErrorCount(). */
+			fault_stall_trips++;
 			faultDesyncEpisodeCharge(DESYNC_EPISODE_STALL_RAIL);
 		}
 		if (escIsFault()) {