diff --git a/include/lorawan.h b/include/lorawan.h
index 58b0f3e2..e5af3504 100644
--- a/include/lorawan.h
+++ b/include/lorawan.h
@@ -4,7 +4,7 @@
 #include "globals.h"
 #include "rcommand.h"
 #include "timekeeper.h"
-#if(TIME_SYNC_LORASERVER)
+#if (TIME_SYNC_LORASERVER)
 #include "timesync.h"
 #endif
 
@@ -37,6 +37,9 @@ void switch_lora(uint8_t sf, uint8_t tx);
 void lora_send(void *pvParameters);
 void lora_enqueuedata(MessageBuffer_t *message);
 void lora_queuereset(void);
+void myRxCallback(void *pUserData, uint8_t port, const uint8_t *pMsg,
+                  size_t nMsg);
+void myTxCallback(void *pUserData, int fSuccess);
 #if (TIME_SYNC_LORAWAN)
 void user_request_network_time_callback(void *pVoidUserUTCTime,
                                         int flagSuccess);
diff --git a/include/rcommand.h b/include/rcommand.h
index e964eb85..7895c257 100644
--- a/include/rcommand.h
+++ b/include/rcommand.h
@@ -23,7 +23,7 @@ typedef struct {
   const bool store;
 } cmd_t;
 
-void rcommand(uint8_t cmd[], uint8_t cmdlength);
+void rcommand(const uint8_t cmd[], const uint8_t cmdlength);
 void do_reset();
 
 #endif
diff --git a/include/timesync.h b/include/timesync.h
index 7a0013ec..c102c1c4 100644
--- a/include/timesync.h
+++ b/include/timesync.h
@@ -12,7 +12,7 @@
 
 void timesync_init(void);
 void send_timesync_req(void);
-int recv_timesync_ans(uint8_t seq_no, uint8_t buf[], uint8_t buf_len);
+int recv_timesync_ans(const uint8_t seq_no, const uint8_t buf[], const uint8_t buf_len);
 void process_timesync_req(void *taskparameter);
 void store_time_sync_req(uint32_t t_millisec);
 
diff --git a/src/lmic_config.h b/src/lmic_config.h
index f4ddf4ab..fb6fc771 100644
--- a/src/lmic_config.h
+++ b/src/lmic_config.h
@@ -19,10 +19,15 @@
 // LMIC LORAWAN STACK SETTINGS
 // --> adapt to your device only if necessary
 
+// use interrupts only if LORA_IRQ and LORA_DIO are connected to interrupt
+// capable GPIO pins on your board, if not disable interrupts
 //#define LMIC_USE_INTERRUPTS 1
 
-//time sync via LoRaWAN network, is not yet supported by TTN (LoRaWAN spec v1.0.3)
-//#define LMIC_ENABLE_DeviceTimeReq 1
+// needed for paxcounter code
+#define LMIC_ENABLE_user_events 1
+
+// time sync via LoRaWAN network, note: not supported by TTNv2
+// #define LMIC_ENABLE_DeviceTimeReq 1
 
 // 16 μs per tick
 // LMIC requires ticks to be 15.5μs - 100 μs long
@@ -33,7 +38,7 @@
 // This tells LMIC to make the receive windows bigger, in case your clock is
 // faster or slower. This causes the transceiver to be earlier switched on,
 // so consuming more power. You may sharpen (reduce) this value if you are
-// limited on battery. 
+// limited on battery.
 // ATTN: VALUES > 7 WILL CAUSE RECEPTION AND JOIN PROBLEMS WITH HIGH SF RATES
 #define CLOCK_ERROR_PROCENTAGE 7
 
diff --git a/src/lorawan.cpp b/src/lorawan.cpp
index 2329eed3..ae019276 100644
--- a/src/lorawan.cpp
+++ b/src/lorawan.cpp
@@ -244,38 +244,6 @@ void onEvent(ev_t ev) {
     strcpy_P(buff, (LMIC.txrxFlags & TXRX_ACK) ? PSTR("RECEIVED ACK")
                                                : PSTR("TX COMPLETE"));
     sprintf(display_line6, " "); // clear previous lmic status
-
-    if (LMIC.dataLen) { // did we receive payload data -> display info
-      ESP_LOGI(TAG, "Received %d bytes of payload, RSSI %d SNR %d",
-               LMIC.dataLen, LMIC.rssi, LMIC.snr / 4);
-      sprintf(display_line6, "RSSI %d SNR %d", LMIC.rssi, LMIC.snr / 4);
-
-      if (LMIC.txrxFlags & TXRX_PORT) { // FPort -> use to switch
-
-        switch (LMIC.frame[LMIC.dataBeg - 1]) {
-
-        case RCMDPORT: // opcode -> call rcommand interpreter
-          rcommand(LMIC.frame + LMIC.dataBeg, LMIC.dataLen);
-          break;
-
-        default:
-
-#if (TIME_SYNC_LORASERVER)
-          // timesync answer -> call timesync processor
-          if ((LMIC.frame[LMIC.dataBeg - 1] >= TIMEANSWERPORT_MIN) &&
-              (LMIC.frame[LMIC.dataBeg - 1] <= TIMEANSWERPORT_MAX)) {
-            recv_timesync_ans(LMIC.frame[LMIC.dataBeg - 1],
-                              LMIC.frame + LMIC.dataBeg, LMIC.dataLen);
-            break;
-          }
-#endif
-          // unknown port -> display info
-          ESP_LOGI(TAG, "Received data on unsupported port #%d",
-                   LMIC.frame[LMIC.dataBeg - 1]);
-          break;
-        }
-      }
-    }
     break;
 
   case EV_LOST_TSYNC:
@@ -402,9 +370,10 @@ void lora_send(void *pvParameters) {
     // attempt to transmit payload
     else {
 
-      switch (LMIC_setTxData2(SendBuffer.MessagePort, SendBuffer.Message,
-                              SendBuffer.MessageSize,
-                              (cfg.countermode & 0x02))) {
+      switch (LMIC_sendWithCallback(
+          SendBuffer.MessagePort, SendBuffer.Message, SendBuffer.MessageSize,
+          (cfg.countermode & 0x02), myTxCallback, NULL)) {
+
       case 0:
         ESP_LOGI(TAG, "%d byte(s) delivered to LMIC", SendBuffer.MessageSize);
         break;
@@ -554,6 +523,9 @@ void lmictask(void *pvParameters) {
   // rate for 125 kHz channels, and it minimizes air time and battery power.
   // Set the transmission power to 14 dBi (25 mW).
   LMIC_setDrTxpow(DR_SF7, 14);
+  // register a callback for downlink messages. We aren't trying to write
+  // reentrant code, so pUserData is NULL.
+  LMIC_registerRxMessageCb(myRxCallback, NULL);
 
 #if defined(CFG_US915) || defined(CFG_au921)
   // in the US, with TTN, it saves join time if we start on subband 1
@@ -569,4 +541,41 @@ void lmictask(void *pvParameters) {
   }
 } // lmictask
 
-#endif // HAS_LORA
+// receive message handler
+void myRxCallback(void *pUserData, uint8_t port, const uint8_t *pMsg,
+                  size_t nMsg) {
+
+  // did we receive payload data -> display info
+  if (nMsg)
+    ESP_LOGI(TAG, "Received %d bytes of payload on port %d", nMsg, port);
+
+  switch (port) {
+
+    // ignore mac messages
+  case MACPORT:
+    break;
+
+  // rcommand received -> call interpreter
+  case RCMDPORT:
+    rcommand(pMsg, nMsg);
+    break;
+
+  default:
+
+#if (TIME_SYNC_LORASERVER)
+    // valid timesync answer -> call timesync processor
+    if ((port >= TIMEANSWERPORT_MIN) && (port <= TIMEANSWERPORT_MAX))
+      recv_timesync_ans(port, pMsg, nMsg);
+    break;
+#endif
+
+    // unknown port -> display info
+    ESP_LOGI(TAG, "Received data on unsupported port %d", port);
+    break;
+  } // switch
+}
+
+// transmit complete message handler
+void myTxCallback(void *pUserData, int fSuccess) { /* currently unused */ }
+
+#endif // HAS_LORA
\ No newline at end of file
diff --git a/src/paxcounter.conf b/src/paxcounter.conf
index 7382d8d8..d78d0035 100644
--- a/src/paxcounter.conf
+++ b/src/paxcounter.conf
@@ -85,6 +85,7 @@
 
 // Ports on which the device sends and listenes on LoRaWAN and SPI
 #define COUNTERPORT                     1       // counts
+#define MACPORT                         0       // network commands
 #define RCMDPORT                        2       // remote commands
 #define STATUSPORT                      2       // remote command results
 #define CONFIGPORT                      3       // config query results
diff --git a/src/rcommand.cpp b/src/rcommand.cpp
index 33acf703..2f2e14ca 100644
--- a/src/rcommand.cpp
+++ b/src/rcommand.cpp
@@ -353,7 +353,7 @@ const uint8_t cmdtablesize =
     sizeof(table) / sizeof(table[0]); // number of commands in command table
 
 // check and execute remote command
-void rcommand(uint8_t cmd[], uint8_t cmdlength) {
+void rcommand(const uint8_t cmd[], const uint8_t cmdlength) {
 
   if (cmdlength == 0)
     return;
diff --git a/src/timesync.cpp b/src/timesync.cpp
index 524ac10f..8ce3238f 100644
--- a/src/timesync.cpp
+++ b/src/timesync.cpp
@@ -154,7 +154,7 @@ void store_time_sync_req(uint32_t timestamp) {
 }
 
 // process timeserver timestamp answer, called from lorawan.cpp
-int recv_timesync_ans(uint8_t seq_no, uint8_t buf[], uint8_t buf_len) {
+int recv_timesync_ans(const uint8_t seq_no, const uint8_t buf[], const uint8_t buf_len) {
 
   // if no timesync handshake is pending then exit
   if (!timeSyncPending)