consolidate redundant sml energy fields

src/lora.cpp

 static bool lora_tx(enum lora_sml_type type, double value) {
     bool tx_legal = millis() > (last_tx + minimum_pause);
     if (!tx_legal) {
-        //debug.printf("Legal limit, wait %i sec.\n", (int)((minimum_pause - (millis() - last_tx)) / 1000) + 1);
         return false;
     }
 
     uint8_t *data = (uint8_t *)&msg;
     const size_t len = sizeof(struct lora_sml_msg);
 
+    debug.printf("TX [%d] (%lu) ", data[0], len);
+
 #ifdef LORA_XOR_KEY
     for (size_t i = 0; i < len; i++) {
         data[i] ^= LORA_XOR_KEY[i];
     }
 #endif
 
-    debug.printf("TX [%d] (%lu) ", data[0], len);
     radio.clearDio1Action();
 
     heltec_led(LORA_LED_BRIGHTNESS);
         return;
     }
 
-    // If a packet was received, display it and the RSSI and SNR
     if (rx_flag) {
         rx_flag = false;
 

src/smart_meter.cpp

 
         if (!isnan(SumWh)) {
             debug.printf("Sum: %14.3lf Wh\n", SumWh);
-#ifdef FEATURE_LORA
-            lora_sml_send(LORA_SML_SUM_WH, SumWh, counter);
-#endif // FEATURE_LORA
         }
 
         if (!isnan(T1Wh)) {
             debug.printf(" T1: %14.3lf Wh\n", T1Wh);
-#ifdef FEATURE_LORA
-            lora_sml_send(LORA_SML_T1_WH, T1Wh, counter);
-#endif // FEATURE_LORA
         }
 
         if (!isnan(T2Wh)) {
             debug.printf(" T2: %14.3lf Wh\n", T2Wh);
-#ifdef FEATURE_LORA
-            lora_sml_send(LORA_SML_T2_WH, T2Wh, counter);
-#endif // FEATURE_LORA
         }
 
         if (!isnan(SumW)) {
             debug.printf("Sum: %14.3lf W\n", SumW);
+
 #ifdef FEATURE_LORA
             lora_sml_send(LORA_SML_SUM_W, SumW, counter);
 #endif // FEATURE_LORA
 
         if (!isnan(L2W)) {
             debug.printf(" L2: %14.3lf W\n", L2W);
+
 #ifdef FEATURE_LORA
             lora_sml_send(LORA_SML_L2_W, L2W, counter);
 #endif // FEATURE_LORA
 
         if (!isnan(L3W)) {
             debug.printf(" L3: %14.3lf W\n", L3W);
+
 #ifdef FEATURE_LORA
             lora_sml_send(LORA_SML_L3_W, L3W, counter);
 #endif // FEATURE_LORA
         }
 
+        debug.println();
+
 #ifdef FEATURE_LORA
+        // the power readings (Watt) are just sent as is, if available.
+        // the energy readings are consolidated if possible, to avoid
+        // unneccessary data transmission
+        if ((!isnan(SumWh)) && (!isnan(T1Wh))
+                && (fabs(SumWh - T1Wh) < 0.1)
+                && ((isnan(T2Wh)) || (fabs(T2Wh) < 0.1))) {
+            // (SumWh == T1Wh) && ((T2Wh == 0) || (T2Wh == NAN))
+            // just send T1Wh
+            lora_sml_send(LORA_SML_T1_WH, T1Wh, counter);
+        } else if ((!isnan(SumWh)) && (!isnan(T2Wh))
+                && (fabs(SumWh - T2Wh) < 0.1)
+                && ((isnan(T1Wh)) || (fabs(T1Wh) < 0.1))) {
+            // (SumWh == T2Wh) && ((T1Wh == 0) || (T1Wh == NAN))
+            // just send T2Wh
+            lora_sml_send(LORA_SML_T2_WH, T2Wh, counter);
+        } else {
+            // just do normal sending if available
+            if (!isnan(SumWh)) {
+                lora_sml_send(LORA_SML_SUM_WH, SumWh, counter);
+            }
+            if (!isnan(T1Wh)) {
+                lora_sml_send(LORA_SML_T1_WH, T1Wh, counter);
+            }
+            if (!isnan(T2Wh)) {
+                lora_sml_send(LORA_SML_T2_WH, T2Wh, counter);
+            }
+        }
+
+        // update own battery state with each sml readout
         lora_sml_send(LORA_SML_BAT_V, lora_get_mangled_bat(), counter);
 #endif // FEATURE_LORA
-
-        debug.println();
     }
 }