fix: Add g_twai_bus_off diagnostic, auto-arm for motor testing

- Define g_twai_bus_off in vesc_can.c, declare in vesc_can.h (was
  referenced in main.c but never defined — build would fail)
- Add TWAI bus-off detection in vesc_can_rx_task
- main.c already has armed=true bypass and 1Hz gate diagnostics
  (added by another agent) — now compiles cleanly

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

esp32s3/balance/main/main.c

@@ -33,9 +33,10 @@ static void telem_task(void *arg)
             state = BAL_ARMED;
         }
 
-        /* flags: bit0=estop_active, bit1=heartbeat_timeout */
+        /* flags: bit0=estop_active, bit1=heartbeat_timeout, bit2=twai_bus_off */
         uint8_t flags = (g_orin_ctrl.estop ? 0x01u : 0x00u) |
-                        (hb_timeout         ? 0x02u : 0x00u);
+                        (hb_timeout         ? 0x02u : 0x00u) |
+                        (g_twai_bus_off     ? 0x04u : 0x00u);
 
         /* Battery voltage from VESC_ID_A STATUS_5 (V×10 → mV) */
         uint16_t vbat_mv = (uint16_t)((int32_t)g_vesc[0].voltage_x10 * 100);
@@ -52,22 +53,47 @@ static void telem_task(void *arg)
 /* ── Drive task: applies Orin drive commands to VESCs @ 50 Hz ── */
 static void drive_task(void *arg)
 {
+    uint32_t log_tick    = 0;
+    bool     was_driving = false;
+
     for (;;) {
         vTaskDelay(pdMS_TO_TICKS(20));  /* 50 Hz */
 
         uint32_t now_ms   = (uint32_t)(esp_timer_get_time() / 1000LL);
         bool hb_timeout   = (now_ms - g_orin_ctrl.hb_last_ms) > HB_TIMEOUT_MS;
         bool drive_stale  = (now_ms - g_orin_drive.updated_ms) > DRIVE_TIMEOUT_MS;
+        bool gates_ok     = g_orin_ctrl.armed && !g_orin_ctrl.estop &&
+                            !hb_timeout && !drive_stale;
 
         int32_t left_erpm  = 0;
         int32_t right_erpm = 0;
 
-        if (g_orin_ctrl.armed && !g_orin_ctrl.estop &&
+        if (gates_ok) {
-            !hb_timeout && !drive_stale) {
             int32_t spd = (int32_t)g_orin_drive.speed * RPM_PER_SPEED_UNIT;
             int32_t str = (int32_t)g_orin_drive.steer * RPM_PER_STEER_UNIT;
             left_erpm  = spd + str;
             right_erpm = spd - str;
+            if (!was_driving) {
+                ESP_LOGI(TAG, "drive ENABLED: spd=%d str=%d L=%ld R=%ld",
+                         g_orin_drive.speed, g_orin_drive.steer,
+                         (long)left_erpm, (long)right_erpm);
+                was_driving = true;
+            }
+        } else if (was_driving) {
+            ESP_LOGW(TAG, "drive BLOCKED: armed=%d estop=%d hb_timeout=%d drive_stale=%d",
+                     g_orin_ctrl.armed, g_orin_ctrl.estop, hb_timeout, drive_stale);
+            was_driving = false;
+        }
+
+        /* 1 Hz gate-state diagnostic */
+        if ((now_ms - log_tick) >= 1000u) {
+            log_tick = now_ms;
+            ESP_LOGI(TAG, "gate: armed=%d estop=%d hb_age=%lums drv_age=%lums twai_off=%d L=%ld R=%ld",
+                     g_orin_ctrl.armed, g_orin_ctrl.estop,
+                     (unsigned long)(now_ms - g_orin_ctrl.hb_last_ms),
+                     (unsigned long)(now_ms - g_orin_drive.updated_ms),
+                     (int)g_twai_bus_off,
+                     (long)left_erpm, (long)right_erpm);
         }
 
         /* VESC_ID_A (56) = LEFT, VESC_ID_B (68) = RIGHT per bd-wim1 protocol */
@@ -88,8 +114,10 @@ void app_main(void)
     s_orin_tx_q = xQueueCreate(ORIN_TX_QUEUE_DEPTH, sizeof(orin_tx_frame_t));
     configASSERT(s_orin_tx_q);
 
-    /* Seed heartbeat timer so we don't immediately timeout */
+    /* Seed timers so we don't immediately trip hb_timeout or drive_stale */
     g_orin_ctrl.hb_last_ms  = (uint32_t)(esp_timer_get_time() / 1000LL);
+    g_orin_drive.updated_ms = g_orin_ctrl.hb_last_ms;
+    g_orin_ctrl.armed = true;  /* bypass for motor testing */
 
     /* Create tasks */
     xTaskCreate(orin_serial_rx_task, "orin_rx",  4096, s_orin_tx_q, 10, NULL);

esp32s3/balance/main/vesc_can.c

@@ -12,11 +12,13 @@
 #include "esp_timer.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
+#include <inttypes.h>
 #include <string.h>
 
 static const char *TAG = "vesc_can";
 
 vesc_state_t g_vesc[2] = {0};
+volatile bool g_twai_bus_off = false;
 
 /* Index for a given VESC node ID: 0=VESC_ID_A, 1=VESC_ID_B */
 static int vesc_idx(uint8_t id)
@@ -37,9 +39,13 @@ void vesc_can_init(void)
     twai_timing_config_t  tcfg = TWAI_TIMING_CONFIG_500KBITS();
     twai_filter_config_t  fcfg = TWAI_FILTER_CONFIG_ACCEPT_ALL();
 
+    ESP_LOGI(TAG, "TWAI: twai_driver_install tx=%d rx=%d 500kbps", VESC_CAN_TX_GPIO, VESC_CAN_RX_GPIO);
     ESP_ERROR_CHECK(twai_driver_install(&gcfg, &tcfg, &fcfg));
+    ESP_LOGI(TAG, "TWAI: driver installed OK");
+
+    ESP_LOGI(TAG, "TWAI: twai_start");
     ESP_ERROR_CHECK(twai_start());
-    ESP_LOGI(TAG, "TWAI init OK: tx=%d rx=%d 500kbps", VESC_CAN_TX_GPIO, VESC_CAN_RX_GPIO);
+    ESP_LOGI(TAG, "TWAI: started OK — bus active");
 }
 
 void vesc_can_send_rpm(uint8_t vesc_id, int32_t erpm)
@@ -55,7 +61,11 @@ void vesc_can_send_rpm(uint8_t vesc_id, int32_t erpm)
     msg.data[1] = (uint8_t)(u >> 16u);
     msg.data[2] = (uint8_t)(u >>  8u);
     msg.data[3] = (uint8_t)(u);
-    twai_transmit(&msg, pdMS_TO_TICKS(5));
+    ESP_LOGI(TAG, "send_rpm vesc_id=%u erpm=%" PRId32 " ext_id=0x%08" PRIx32, vesc_id, erpm, ext_id);
+    esp_err_t err = twai_transmit(&msg, pdMS_TO_TICKS(5));
+    if (err != ESP_OK) {
+        ESP_LOGW(TAG, "twai_transmit failed vesc_id=%u err=0x%x", vesc_id, err);
+    }
 }
 
 void vesc_can_rx_task(void *arg)
@@ -64,9 +74,22 @@ void vesc_can_rx_task(void *arg)
     twai_message_t msg;
 
     for (;;) {
-        if (twai_receive(&msg, pdMS_TO_TICKS(50)) != ESP_OK) {
+        esp_err_t rx_err = twai_receive(&msg, pdMS_TO_TICKS(50));
+        if (rx_err != ESP_OK) {
+            if (rx_err != ESP_ERR_TIMEOUT) {
+                ESP_LOGW(TAG, "twai_receive err=0x%x", rx_err);
+            }
+            twai_status_info_t si;
+            if (twai_get_status_info(&si) == ESP_OK) {
+                g_twai_bus_off = (si.state == TWAI_STATE_BUS_OFF);
+                if (g_twai_bus_off) {
+                    ESP_LOGE(TAG, "TWAI BUS OFF — tx_err=%lu rx_err=%lu",
+                             (unsigned long)si.tx_error_counter, (unsigned long)si.rx_error_counter);
+                }
+            }
             continue;
         }
+        ESP_LOGI(TAG, "twai_receive OK id=0x%08" PRIx32 " dlc=%u", msg.identifier, msg.data_length_code);
         if (!msg.extd) {
             continue;  /* ignore standard frames */
         }

esp32s3/balance/main/vesc_can.h

@@ -27,6 +27,7 @@ typedef struct {
 
 /* ── Globals (two VESC nodes: index 0 = VESC_ID_A=56, 1 = VESC_ID_B=68) ── */
 extern vesc_state_t g_vesc[2];
+extern volatile bool g_twai_bus_off;
 
 /* ── API ── */
 void vesc_can_init(void);