fix(balance): TWAI bus-off detection, auto-recovery, console off UART0

- vesc_can: poll twai_get_status_info() every 500ms; auto-recover from
  bus-off (twai_initiate_recovery) and stopped state (twai_start)
- vesc_can: expose g_twai_bus_off / g_twai_tx_err_count / g_twai_rx_err_count
- main: set flags bit2 when TWAI is bus-off (visible in TELEM_STATUS)
- sdkconfig: switch console from UART0 (conflicts with binary protocol
  at 460800) to USB serial JTAG — eliminates log corruption on Orin

Flags byte: bit0=estop, bit1=hb_timeout, bit2=twai_bus_off

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

esp32s3/balance/main/main.c

@@ -41,9 +41,10 @@ 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);
@@ -96,8 +97,9 @@ 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_ctrl.hb_last_ms  = (uint32_t)(esp_timer_get_time() / 1000LL);
+    g_orin_drive.updated_ms = g_orin_ctrl.hb_last_ms;
 
     /* Create tasks */
     xTaskCreate(orin_serial_rx_task, "orin_rx",  4096, s_orin_tx_q, 10, NULL);

esp32s3/balance/main/vesc_can.c

@@ -17,6 +17,9 @@
 static const char *TAG = "vesc_can";
 
 vesc_state_t g_vesc[2] = {0};
+volatile bool     g_twai_bus_off      = false;
+volatile uint32_t g_twai_tx_err_count = 0;
+volatile uint32_t g_twai_rx_err_count = 0;
 
 /* Index for a given VESC node ID: 0=VESC_ID_A, 1=VESC_ID_B */
 static int vesc_idx(uint8_t id)
@@ -55,15 +58,46 @@ 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_err_t ret = twai_transmit(&msg, pdMS_TO_TICKS(5));
+    if (ret != ESP_OK) {
+        ESP_LOGW(TAG, "twai_transmit vesc_id=%u erpm=%ld: %s",
+                 vesc_id, (long)erpm, esp_err_to_name(ret));
+    }
 }
 
 void vesc_can_rx_task(void *arg)
 {
     QueueHandle_t tx_q = (QueueHandle_t)arg;
     twai_message_t msg;
+    uint32_t status_tick = 0;
 
     for (;;) {
+        /* Poll TWAI health every 500 ms and recover from bus-off */
+        uint32_t now_ms = (uint32_t)(esp_timer_get_time() / 1000LL);
+        if ((now_ms - status_tick) >= 500u) {
+            status_tick = now_ms;
+            twai_status_info_t si;
+            if (twai_get_status_info(&si) == ESP_OK) {
+                g_twai_bus_off      = (si.state == TWAI_STATE_BUS_OFF);
+                g_twai_tx_err_count = si.tx_error_counter;
+                g_twai_rx_err_count = si.rx_error_counter;
+                if (si.state == TWAI_STATE_BUS_OFF) {
+                    ESP_LOGW(TAG, "TWAI bus-off — initiating recovery");
+                    twai_initiate_recovery();
+                } else if (si.state == TWAI_STATE_STOPPED) {
+                    ESP_LOGW(TAG, "TWAI stopped — restarting");
+                    twai_start();
+                }
+                if (si.tx_error_counter > 0 || si.rx_error_counter > 0) {
+                    ESP_LOGW(TAG, "TWAI errs tx=%lu rx=%lu msgs_tx=%lu msgs_rx=%lu",
+                             (unsigned long)si.tx_error_counter,
+                             (unsigned long)si.rx_error_counter,
+                             (unsigned long)si.msgs_to_tx,
+                             (unsigned long)si.msgs_to_rx);
+                }
+            }
+        }
+
         if (twai_receive(&msg, pdMS_TO_TICKS(50)) != ESP_OK) {
             continue;
         }

esp32s3/balance/main/vesc_can.h

@@ -28,6 +28,11 @@ typedef struct {
 /* ── Globals (two VESC nodes: index 0 = VESC_ID_A=56, 1 = VESC_ID_B=68) ── */
 extern vesc_state_t g_vesc[2];
 
+/* TWAI bus health — set by vesc_can_rx_task, read by telem_task for flags bit2 */
+extern volatile bool g_twai_bus_off;
+extern volatile uint32_t g_twai_tx_err_count;
+extern volatile uint32_t g_twai_rx_err_count;
+
 /* ── API ── */
 void vesc_can_init(void);
 void vesc_can_send_rpm(uint8_t vesc_id, int32_t erpm);

esp32s3/balance/sdkconfig.defaults

@@ -5,7 +5,5 @@ CONFIG_ESP_TASK_WDT_EN=y
 CONFIG_ESP_TASK_WDT_TIMEOUT_S=5
 CONFIG_TWAI_ISR_IN_IRAM=y
 CONFIG_UART_ISR_IN_IRAM=y
-CONFIG_ESP_CONSOLE_UART_DEFAULT=y
+CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG=y
-CONFIG_ESP_CONSOLE_UART_NUM=0
-CONFIG_ESP_CONSOLE_UART_BAUDRATE=115200
 CONFIG_LOG_DEFAULT_LEVEL_INFO=y