count timeouts to detect offline state

lib/nmea2ktwai/Nmea2kTwai.cpp

@@ -20,9 +20,13 @@ bool Nmea2kTwai::CANSendFrame(unsigned long id, unsigned char len, const unsigne
     memcpy(message.data,buf,len);
     esp_err_t rt=twai_transmit(&message,0);
     if (rt != ESP_OK){
-        logDebug(LOG_DEBUG,"twai transmit for %ld failed: %x",LOGID(id),(int)rt);
+        if (rt == ESP_ERR_TIMEOUT){
+            txTimeouts++;
+        }
+        logDebug(LOG_MSG,"twai transmit for %ld failed: %x",LOGID(id),(int)rt);
         return false;
     }
+    txTimeouts=0;
     logDebug(LOG_MSG,"twai transmit id %ld, len %d",LOGID(id),(int)len);
     return true;
 }
@@ -106,6 +110,10 @@ Nmea2kTwai::Status Nmea2kTwai::getStatus(){
     rt.tx_failed=state.tx_failed_count;
     rt.rx_missed=state.rx_missed_count;
     rt.rx_overrun=state.rx_overrun_count;
+    rt.tx_timeouts=txTimeouts;
+    if (rt.tx_timeouts > 256 && rt.state == ST_RUNNING){
+        rt.state=ST_OFFLINE;
+    }
     return rt;
 }
 
@@ -125,6 +133,7 @@ const char * Nmea2kTwai::stateStr(const Nmea2kTwai::STATE &st){
     case ST_RECOVERING: return "RECOVERING";
     case ST_RUNNING: return "RUNNING";
     case ST_STOPPED: return "STOPPED";
+    case ST_OFFLINE: return "OFFLINE";
     }
     return "ERROR";
 }

lib/nmea2ktwai/Nmea2kTwai.h

@@ -11,6 +11,7 @@ class Nmea2kTwai : public tNMEA2000{
             ST_RUNNING,
             ST_BUS_OFF,
             ST_RECOVERING,
+            ST_OFFLINE,
             ST_ERROR
         } STATE;
         typedef struct{
@@ -20,6 +21,7 @@ class Nmea2kTwai : public tNMEA2000{
             uint32_t tx_failed=0;
             uint32_t rx_missed=0;
             uint32_t rx_overrun=0;
+            uint32_t tx_timeouts=0;
             STATE state=ST_ERROR;
         } Status;
         Status getStatus();
@@ -47,6 +49,7 @@ class Nmea2kTwai : public tNMEA2000{
     void initDriver();
     gpio_num_t TxPin;  
     gpio_num_t RxPin;
+    uint32_t txTimeouts=0;
 };
 
 #endif

src/main.cpp

@@ -861,11 +861,13 @@ void loop() {
   if (now > (lastCanRecovery + CAN_RECOVERY_PERIOD)){
     lastCanRecovery=now;
     Nmea2kTwai::Status canState=NMEA2000.getStatus();
-    logger.logDebug(GwLog::DEBUG,"can state %s, rxerr %d, txerr %d, txfail %d, rxmiss %d, rxoverrun %d",
+    logger.logDebug(GwLog::DEBUG,
+      "can state %s, rxerr %d, txerr %d, txfail %d, txtimeout %d, rxmiss %d, rxoverrun %d",
       NMEA2000.stateStr(canState.state),
       canState.rx_errors,
       canState.tx_errors,
       canState.tx_failed,
+      canState.tx_timeouts,
       canState.rx_missed,
       canState.rx_overrun);
     if (canState.state != Nmea2kTwai::ST_RUNNING){