diff --git a/examples/companion_radio/UITask.cpp b/examples/companion_radio/UITask.cpp
index f4e3fb0b..675972dc 100644
--- a/examples/companion_radio/UITask.cpp
+++ b/examples/companion_radio/UITask.cpp
@@ -266,7 +266,7 @@ void UITask::buttonHandler() {
             digitalWrite(PIN_STATUS_LED, LOW);
             delay(10);
           #endif
-            _board->powerOff();
+            shutdown(); // without restart
           }
         }
         btn_state_change_time = millis();
@@ -278,6 +278,30 @@ void UITask::buttonHandler() {
   #endif
   }
 
+
+/* hardware-agnostic pre-shutdown activity should be done here 
+*/
+void UITask::shutdown(bool restart){
+
+  #ifdef PIN_BUZZER
+  /* note: we have a choice here -
+     we can do a blocking buzzer.loop() with non-deterministic consequences
+     or we can set a flag and delay the shutdown for a couple of seconds
+     while a non-blocking buzzer.loop() plays out in UITask::loop()
+  */
+  buzzer.shutdown();
+  uint32_t buzzer_timer = millis(); // fail-safe shutdown
+  while (buzzer.isPlaying() && (millis() - 2500) < buzzer_timer)
+    buzzer.loop();
+
+  #endif // PIN_BUZZER
+
+  if (restart)
+    _board->reboot();
+  else
+    _board->powerOff();
+}
+
 void UITask::loop() {
   buttonHandler();
   userLedHandler();
diff --git a/examples/companion_radio/UITask.h b/examples/companion_radio/UITask.h
index 134b5a16..d774e54c 100644
--- a/examples/companion_radio/UITask.h
+++ b/examples/companion_radio/UITask.h
@@ -39,7 +39,6 @@ class UITask {
   void buttonHandler();
   void userLedHandler();
   void renderBatteryIndicator(uint16_t batteryMilliVolts);
-
  
 public:
 
@@ -55,5 +54,6 @@ public:
   void msgRead(int msgcount);
   void newMsg(uint8_t path_len, const char* from_name, const char* text, int msgcount);
   void soundBuzzer(UIEventType bet = UIEventType::none);
+  void shutdown(bool restart = false);
   void loop();
 };
diff --git a/examples/companion_radio/main.cpp b/examples/companion_radio/main.cpp
index 13db88c0..30a1c9cc 100644
--- a/examples/companion_radio/main.cpp
+++ b/examples/companion_radio/main.cpp
@@ -57,6 +57,7 @@
 #define FLOOD_SEND_TIMEOUT_FACTOR         16.0f
 #define DIRECT_SEND_PERHOP_FACTOR         6.0f
 #define DIRECT_SEND_PERHOP_EXTRA_MILLIS   250
+#define LAZY_CONTACTS_WRITE_DELAY        5000
 
 #define  PUBLIC_GROUP_PSK  "izOH6cXN6mrJ5e26oRXNcg=="
 
@@ -198,6 +199,7 @@ class MyMesh : public BaseChatMesh {
   uint8_t app_target_ver;
   uint8_t* sign_data;
   uint32_t sign_data_len;
+  unsigned long dirty_contacts_expiry;
   uint8_t cmd_frame[MAX_FRAME_SIZE+1];
   uint8_t out_frame[MAX_FRAME_SIZE+1];
   CayenneLPP telemetry;
@@ -488,6 +490,10 @@ protected:
     return _prefs.airtime_factor;
   }
 
+  int getInterferenceThreshold() const override {
+    return 14;  // hard-coded for now
+  }
+
   int calcRxDelay(float score, uint32_t air_time) const override {
     if (_prefs.rx_delay_base <= 0.0f) return 0;
     return (int) ((pow(_prefs.rx_delay_base, 0.85f - score) - 1.0) * air_time);
@@ -524,7 +530,7 @@ protected:
     #endif
     }
 
-    saveContacts();
+    dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);
   }
 
   void onContactPathUpdated(const ContactInfo& contact) override {
@@ -532,7 +538,7 @@ protected:
     memcpy(&out_frame[1], contact.id.pub_key, PUB_KEY_SIZE);
     _serial->writeFrame(out_frame, 1 + PUB_KEY_SIZE);   // NOTE: app may not be connected
 
-    saveContacts();
+    dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);
   }
 
   bool processAck(const uint8_t *data) override {
@@ -603,7 +609,8 @@ protected:
 
   void onSignedMessageRecv(const ContactInfo& from, mesh::Packet* pkt, uint32_t sender_timestamp, const uint8_t *sender_prefix, const char *text) override {
     markConnectionActive(from);
-    saveContacts();   // from.sync_since change needs to be persisted
+    // from.sync_since change needs to be persisted
+    dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);
     queueMessage(from, TXT_TYPE_SIGNED_PLAIN, pkt, sender_timestamp, sender_prefix, 4, text);
   }
 
@@ -695,6 +702,7 @@ protected:
       if (memcmp(&data[4], "OK", 2) == 0) {    // legacy Repeater login OK response
         out_frame[i++] = PUSH_CODE_LOGIN_SUCCESS;
         out_frame[i++] = 0;  // legacy: is_admin = false
+        memcpy(&out_frame[i], contact.id.pub_key, 6); i += 6;  // pub_key_prefix
       } else if (data[4] == RESP_SERVER_LOGIN_OK) {   // new login response
         uint16_t keep_alive_secs = ((uint16_t)data[5]) * 16;
         if (keep_alive_secs > 0) {
@@ -702,11 +710,13 @@ protected:
         }
         out_frame[i++] = PUSH_CODE_LOGIN_SUCCESS;
         out_frame[i++] = data[6];  // permissions (eg. is_admin)
+        memcpy(&out_frame[i], contact.id.pub_key, 6); i += 6;  // pub_key_prefix
+        memcpy(&out_frame[i], &tag, 4); i += 4;  // NEW: include server timestamp
       } else {
         out_frame[i++] = PUSH_CODE_LOGIN_FAIL;
         out_frame[i++] = 0;  // reserved
+        memcpy(&out_frame[i], contact.id.pub_key, 6); i += 6;  // pub_key_prefix
       }
-      memcpy(&out_frame[i], contact.id.pub_key, 6); i += 6;  // pub_key_prefix
       _serial->writeFrame(out_frame, i);
     } else if (len > 4 &&   // check for status response
       pending_status && memcmp(&pending_status, contact.id.pub_key, 4) == 0   // legacy matching scheme
@@ -794,6 +804,7 @@ public:
     pending_login = pending_status = pending_telemetry = 0;
     next_ack_idx = 0;
     sign_data = NULL;
+    dirty_contacts_expiry = 0;
 
     // defaults
     memset(&_prefs, 0, sizeof(_prefs));
@@ -1145,7 +1156,7 @@ public:
       if (recipient) {
         recipient->out_path_len = -1;
         //recipient->lastmod = ??   shouldn't be needed, app already has this version of contact
-        saveContacts();
+        dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);
         writeOKFrame();
       } else {
         writeErrFrame(ERR_CODE_NOT_FOUND);  // unknown contact
@@ -1156,7 +1167,7 @@ public:
       if (recipient) {
         updateContactFromFrame(*recipient, cmd_frame, len);
         //recipient->lastmod = ??   shouldn't be needed, app already has this version of contact
-        saveContacts();
+        dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);
         writeOKFrame();
       } else {
         ContactInfo contact;
@@ -1164,7 +1175,7 @@ public:
         contact.lastmod = getRTCClock()->getCurrentTime();
         contact.sync_since = 0;
         if (addContact(contact)) {
-          saveContacts();
+          dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);
           writeOKFrame();
         } else {
           writeErrFrame(ERR_CODE_TABLE_FULL);
@@ -1174,7 +1185,7 @@ public:
       uint8_t* pub_key = &cmd_frame[1];
       ContactInfo* recipient = lookupContactByPubKey(pub_key, PUB_KEY_SIZE);
       if (recipient && removeContact(*recipient)) {
-        saveContacts();
+        dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);
         writeOKFrame();
       } else {
         writeErrFrame(ERR_CODE_NOT_FOUND);  // not found, or unable to remove
@@ -1293,6 +1304,9 @@ public:
       savePrefs();
       writeOKFrame();
     } else if (cmd_frame[0] == CMD_REBOOT && memcmp(&cmd_frame[1], "reboot", 6) == 0) {
+      if (dirty_contacts_expiry) {  // is there are pending dirty contacts write needed?
+        saveContacts();
+      }
       board.reboot();
     } else if (cmd_frame[0] == CMD_GET_BATTERY_VOLTAGE) {
       uint8_t reply[3];
@@ -1563,6 +1577,12 @@ public:
       checkConnections();
     }
 
+    // is there are pending dirty contacts write needed?
+    if (dirty_contacts_expiry && millisHasNowPassed(dirty_contacts_expiry)) {
+      saveContacts();
+      dirty_contacts_expiry = 0;
+    }
+
   #ifdef DISPLAY_CLASS
     ui_task.setHasConnection(_serial->isConnected());
     ui_task.loop();
diff --git a/examples/simple_repeater/main.cpp b/examples/simple_repeater/main.cpp
index 12c843b7..5db62ff1 100644
--- a/examples/simple_repeater/main.cpp
+++ b/examples/simple_repeater/main.cpp
@@ -79,7 +79,7 @@
 struct RepeaterStats {
   uint16_t batt_milli_volts;
   uint16_t curr_tx_queue_len;
-  uint16_t curr_free_queue_len;
+  int16_t  noise_floor;
   int16_t  last_rssi;
   uint32_t n_packets_recv;
   uint32_t n_packets_sent;
@@ -183,7 +183,7 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
         RepeaterStats stats;
         stats.batt_milli_volts = board.getBattMilliVolts();
         stats.curr_tx_queue_len = _mgr->getOutboundCount(0xFFFFFFFF);
-        stats.curr_free_queue_len = _mgr->getFreeCount();
+        stats.noise_floor = (int16_t)_radio->getNoiseFloor();
         stats.last_rssi = (int16_t) radio_driver.getLastRSSI();
         stats.n_packets_recv = radio_driver.getPacketsRecv();
         stats.n_packets_sent = radio_driver.getPacketsSent();
@@ -327,6 +327,9 @@ protected:
     uint32_t t = (_radio->getEstAirtimeFor(packet->path_len + packet->payload_len + 2) * _prefs.direct_tx_delay_factor);
     return getRNG()->nextInt(0, 6)*t;
   }
+  int getInterferenceThreshold() const override {
+    return _prefs.interference_threshold;
+  }
 
   void onAnonDataRecv(mesh::Packet* packet, uint8_t type, const mesh::Identity& sender, uint8_t* data, size_t len) override {
     if (type == PAYLOAD_TYPE_ANON_REQ) {  // received an initial request by a possible admin client (unknown at this stage)
@@ -565,6 +568,7 @@ public:
     _prefs.advert_interval = 1;  // default to 2 minutes for NEW installs
     _prefs.flood_advert_interval = 3;   // 3 hours
     _prefs.flood_max = 64;
+    _prefs.interference_threshold = 14;  // DB
   }
 
   CommonCLI* getCLI() { return &_cli; }
diff --git a/examples/simple_room_server/main.cpp b/examples/simple_room_server/main.cpp
index dad7ce78..5ba6cbca 100644
--- a/examples/simple_room_server/main.cpp
+++ b/examples/simple_room_server/main.cpp
@@ -126,7 +126,7 @@ struct PostInfo {
 struct ServerStats {
   uint16_t batt_milli_volts;
   uint16_t curr_tx_queue_len;
-  uint16_t curr_free_queue_len;
+  int16_t  noise_floor;
   int16_t  last_rssi;
   uint32_t n_packets_recv;
   uint32_t n_packets_sent;
@@ -287,7 +287,7 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
         ServerStats stats;
         stats.batt_milli_volts = board.getBattMilliVolts();
         stats.curr_tx_queue_len = _mgr->getOutboundCount(0xFFFFFFFF);
-        stats.curr_free_queue_len = _mgr->getFreeCount();
+        stats.noise_floor = (int16_t)_radio->getNoiseFloor();
         stats.last_rssi = (int16_t) radio_driver.getLastRSSI();
         stats.n_packets_recv = radio_driver.getPacketsRecv();
         stats.n_packets_sent = radio_driver.getPacketsSent();
@@ -406,6 +406,9 @@ protected:
     uint32_t t = (_radio->getEstAirtimeFor(packet->path_len + packet->payload_len + 2) * _prefs.direct_tx_delay_factor);
     return getRNG()->nextInt(0, 6)*t;
   }
+  int getInterferenceThreshold() const override {
+    return _prefs.interference_threshold;
+  }
 
   bool allowPacketForward(const mesh::Packet* packet) override {
     if (_prefs.disable_fwd) return false;
@@ -711,6 +714,7 @@ public:
     _prefs.advert_interval = 1;  // default to 2 minutes for NEW installs
     _prefs.flood_advert_interval = 3;   // 3 hours
     _prefs.flood_max = 64;
+    _prefs.interference_threshold = 14;  // DB
   #ifdef ROOM_PASSWORD
     StrHelper::strncpy(_prefs.guest_password, ROOM_PASSWORD, sizeof(_prefs.guest_password));
   #endif
diff --git a/src/Dispatcher.cpp b/src/Dispatcher.cpp
index 3d5b04fc..7ac5cbe3 100644
--- a/src/Dispatcher.cpp
+++ b/src/Dispatcher.cpp
@@ -10,6 +10,10 @@ namespace mesh {
 
 #define MAX_RX_DELAY_MILLIS   32000  // 32 seconds
 
+#ifndef NOISE_FLOOR_CALIB_INTERVAL
+  #define NOISE_FLOOR_CALIB_INTERVAL   2000     // 2 seconds
+#endif
+
 void Dispatcher::begin() {
   n_sent_flood = n_sent_direct = 0;
   n_recv_flood = n_recv_direct = 0;
@@ -36,6 +40,12 @@ uint32_t Dispatcher::getCADFailMaxDuration() const {
 }
 
 void Dispatcher::loop() {
+  if (millisHasNowPassed(next_floor_calib_time)) {
+    _radio->triggerNoiseFloorCalibrate(getInterferenceThreshold());
+    next_floor_calib_time = futureMillis(NOISE_FLOOR_CALIB_INTERVAL);
+  }
+  _radio->loop();
+
   // check for radio 'stuck' in mode other than Rx
   bool is_recv = _radio->isInRecvMode();
   if (is_recv != prev_isrecv_mode) {
diff --git a/src/Dispatcher.h b/src/Dispatcher.h
index d03c9f73..bce13b6b 100644
--- a/src/Dispatcher.h
+++ b/src/Dispatcher.h
@@ -56,6 +56,15 @@ public:
   */
   virtual void onSendFinished() = 0;
 
+  /**
+   * \brief  do any processing needed on each loop cycle
+   */
+  virtual void loop() { }
+
+  virtual int getNoiseFloor() const { return 0; }
+
+  virtual void triggerNoiseFloorCalibrate(int threshold) { }
+
   virtual bool isInRecvMode() const = 0;
 
   /**
@@ -107,6 +116,7 @@ class Dispatcher {
   unsigned long next_tx_time;
   unsigned long cad_busy_start;
   unsigned long radio_nonrx_start;
+  unsigned long next_floor_calib_time;
   bool  prev_isrecv_mode;
   uint32_t n_sent_flood, n_sent_direct;
   uint32_t n_recv_flood, n_recv_direct;
@@ -124,6 +134,7 @@ protected:
   {
     outbound = NULL; total_air_time = 0; next_tx_time = 0;
     cad_busy_start = 0;
+    next_floor_calib_time = 0;
     _err_flags = 0;
     radio_nonrx_start = 0;
     prev_isrecv_mode = true;
@@ -142,6 +153,7 @@ protected:
   virtual int calcRxDelay(float score, uint32_t air_time) const;
   virtual uint32_t getCADFailRetryDelay() const;
   virtual uint32_t getCADFailMaxDuration() const;
+  virtual int getInterferenceThreshold() const { return 0; }    // disabled by default
 
 public:
   void begin();
diff --git a/src/helpers/CommonCLI.cpp b/src/helpers/CommonCLI.cpp
index 8b8296f5..baad8f40 100644
--- a/src/helpers/CommonCLI.cpp
+++ b/src/helpers/CommonCLI.cpp
@@ -56,6 +56,7 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     file.read(pad, 4);   // 120
     file.read((uint8_t *) &_prefs->flood_max, sizeof(_prefs->flood_max));   // 124
     file.read((uint8_t *) &_prefs->flood_advert_interval, sizeof(_prefs->flood_advert_interval));  // 125
+    file.read((uint8_t *) &_prefs->interference_threshold, sizeof(_prefs->interference_threshold));  // 126
 
     // sanitise bad pref values
     _prefs->rx_delay_base = constrain(_prefs->rx_delay_base, 0, 20.0f);
@@ -109,6 +110,7 @@ void CommonCLI::savePrefs(FILESYSTEM* fs) {
     file.write(pad, 4);   // 120
     file.write((uint8_t *) &_prefs->flood_max, sizeof(_prefs->flood_max));   // 124
     file.write((uint8_t *) &_prefs->flood_advert_interval, sizeof(_prefs->flood_advert_interval));  // 125
+    file.write((uint8_t *) &_prefs->interference_threshold, sizeof(_prefs->interference_threshold));  // 126
 
     file.close();
   }
@@ -176,6 +178,8 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
       const char* config = &command[4];
       if (memcmp(config, "af", 2) == 0) {
         sprintf(reply, "> %s", StrHelper::ftoa(_prefs->airtime_factor));
+      } else if (memcmp(config, "int.thresh", 10) == 0) {
+        sprintf(reply, "> %d", (uint32_t) _prefs->interference_threshold);
       } else if (memcmp(config, "allow.read.only", 15) == 0) {
         sprintf(reply, "> %s", _prefs->allow_read_only ? "on" : "off");
       } else if (memcmp(config, "flood.advert.interval", 21) == 0) {
@@ -223,6 +227,10 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
         _prefs->airtime_factor = atof(&config[3]);
         savePrefs();
         strcpy(reply, "OK");
+      } else if (memcmp(config, "int.thresh ", 11) == 0) {
+        _prefs->interference_threshold = atoi(&config[11]);
+        savePrefs();
+        strcpy(reply, "OK");
       } else if (memcmp(config, "allow.read.only ", 16) == 0) {
         _prefs->allow_read_only = memcmp(&config[16], "on", 2) == 0;
         savePrefs();
diff --git a/src/helpers/CommonCLI.h b/src/helpers/CommonCLI.h
index 0e88c266..37402c09 100644
--- a/src/helpers/CommonCLI.h
+++ b/src/helpers/CommonCLI.h
@@ -24,6 +24,7 @@ struct NodePrefs {  // persisted to file
     uint8_t reserved2;
     float bw;
     uint8_t flood_max;
+    uint8_t interference_threshold;
 };
 
 class CommonCLICallbacks {
diff --git a/src/helpers/CustomLLCC68Wrapper.h b/src/helpers/CustomLLCC68Wrapper.h
index c7d95c41..f7dd7a9f 100644
--- a/src/helpers/CustomLLCC68Wrapper.h
+++ b/src/helpers/CustomLLCC68Wrapper.h
@@ -6,18 +6,11 @@
 class CustomLLCC68Wrapper : public RadioLibWrapper {
 public:
   CustomLLCC68Wrapper(CustomLLCC68& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomLLCC68 *)_radio)->isReceiving()) return true;
-
-    idle();  // put sx126x into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomLLCC68 *)_radio)->scanChannel() == RADIOLIB_LORA_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomLLCC68 *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    return ((CustomLLCC68 *)_radio)->getRSSI(false);
   }
   float getLastRSSI() const override { return ((CustomLLCC68 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomLLCC68 *)_radio)->getSNR(); }
diff --git a/src/helpers/CustomLR1110Wrapper.h b/src/helpers/CustomLR1110Wrapper.h
index 3a96d3c2..7e2ffa2d 100644
--- a/src/helpers/CustomLR1110Wrapper.h
+++ b/src/helpers/CustomLR1110Wrapper.h
@@ -6,18 +6,13 @@
 class CustomLR1110Wrapper : public RadioLibWrapper {
 public:
   CustomLR1110Wrapper(CustomLR1110& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomLR1110 *)_radio)->isReceiving()) return true;
-
-    idle();  // put sx126x into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomLR1110 *)_radio)->scanChannel() == RADIOLIB_LORA_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomLR1110 *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    float rssi = -110;
+    ((CustomLR1110 *)_radio)->getRssiInst(&rssi);
+    return rssi;
   }
 
   void onSendFinished() override {
diff --git a/src/helpers/CustomSTM32WLxWrapper.h b/src/helpers/CustomSTM32WLxWrapper.h
index 84f78376..9e2d0441 100644
--- a/src/helpers/CustomSTM32WLxWrapper.h
+++ b/src/helpers/CustomSTM32WLxWrapper.h
@@ -7,18 +7,11 @@
 class CustomSTM32WLxWrapper : public RadioLibWrapper {
 public:
   CustomSTM32WLxWrapper(CustomSTM32WLx& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomSTM32WLx *)_radio)->isReceiving()) return true;
-
-    idle();  // put sx126x into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomSTM32WLx *)_radio)->scanChannel() == RADIOLIB_LORA_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomSTM32WLx *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    return ((CustomSTM32WLx *)_radio)->getRSSI(false);
   }
   float getLastRSSI() const override { return ((CustomSTM32WLx *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomSTM32WLx *)_radio)->getSNR(); }
diff --git a/src/helpers/CustomSX1262Wrapper.h b/src/helpers/CustomSX1262Wrapper.h
index ea2da5fe..119f6dce 100644
--- a/src/helpers/CustomSX1262Wrapper.h
+++ b/src/helpers/CustomSX1262Wrapper.h
@@ -2,23 +2,15 @@
 
 #include "CustomSX1262.h"
 #include "RadioLibWrappers.h"
-#include <math.h>
 
 class CustomSX1262Wrapper : public RadioLibWrapper {
 public:
   CustomSX1262Wrapper(CustomSX1262& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomSX1262 *)_radio)->isReceiving()) return true;
-
-    idle();  // put sx126x into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomSX1262 *)_radio)->scanChannel() == RADIOLIB_LORA_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomSX1262 *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    return ((CustomSX1262 *)_radio)->getRSSI(false);
   }
   float getLastRSSI() const override { return ((CustomSX1262 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomSX1262 *)_radio)->getSNR(); }
diff --git a/src/helpers/CustomSX1268Wrapper.h b/src/helpers/CustomSX1268Wrapper.h
index f9eee447..5d7106b4 100644
--- a/src/helpers/CustomSX1268Wrapper.h
+++ b/src/helpers/CustomSX1268Wrapper.h
@@ -6,18 +6,11 @@
 class CustomSX1268Wrapper : public RadioLibWrapper {
 public:
   CustomSX1268Wrapper(CustomSX1268& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomSX1268 *)_radio)->isReceiving()) return true;
-
-    idle();  // put sx126x into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomSX1268 *)_radio)->scanChannel() == RADIOLIB_LORA_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomSX1268 *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    return ((CustomSX1268 *)_radio)->getRSSI(false);
   }
   float getLastRSSI() const override { return ((CustomSX1268 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomSX1268 *)_radio)->getSNR(); }
diff --git a/src/helpers/CustomSX1276Wrapper.h b/src/helpers/CustomSX1276Wrapper.h
index f9900705..28257990 100644
--- a/src/helpers/CustomSX1276Wrapper.h
+++ b/src/helpers/CustomSX1276Wrapper.h
@@ -6,18 +6,11 @@
 class CustomSX1276Wrapper : public RadioLibWrapper {
 public:
   CustomSX1276Wrapper(CustomSX1276& radio, mesh::MainBoard& board) : RadioLibWrapper(radio, board) { }
-  bool isReceiving() override { 
-    if (((CustomSX1276 *)_radio)->isReceiving()) return true;
-
-    idle();  // put into standby
-    // do some basic CAD (blocks for ~12780 micros (on SF 10)!)
-    bool activity = (((CustomSX1276 *)_radio)->tryScanChannel() == RADIOLIB_PREAMBLE_DETECTED);
-    if (activity) {
-      startRecv();
-    } else {
-      idle();
-    }
-    return activity;
+  bool isReceivingPacket() override { 
+    return ((CustomSX1276 *)_radio)->isReceiving();
+  }
+  float getCurrentRSSI() override {
+    return ((CustomSX1276 *)_radio)->getRSSI(false);
   }
   float getLastRSSI() const override { return ((CustomSX1276 *)_radio)->getRSSI(); }
   float getLastSNR() const override { return ((CustomSX1276 *)_radio)->getSNR(); }
diff --git a/src/helpers/RadioLibWrappers.cpp b/src/helpers/RadioLibWrappers.cpp
index 39fb340e..d37bc498 100644
--- a/src/helpers/RadioLibWrappers.cpp
+++ b/src/helpers/RadioLibWrappers.cpp
@@ -8,6 +8,8 @@
 #define STATE_TX_DONE    4
 #define STATE_INT_READY 16
 
+#define NUM_NOISE_FLOOR_SAMPLES  64
+
 static volatile uint8_t state = STATE_IDLE;
 
 // this function is called when a complete packet
@@ -28,6 +30,13 @@ void RadioLibWrapper::begin() {
   if (_board->getStartupReason() == BD_STARTUP_RX_PACKET) {  // received a LoRa packet (while in deep sleep)
     setFlag(); // LoRa packet is already received
   }
+
+  _noise_floor = 0;
+  _threshold = 0;
+
+  // start average out some samples
+  _num_floor_samples = 0;
+  _floor_sample_sum = 0;
 }
 
 void RadioLibWrapper::idle() {
@@ -35,6 +44,31 @@ void RadioLibWrapper::idle() {
   state = STATE_IDLE;   // need another startReceive()
 }
 
+void RadioLibWrapper::triggerNoiseFloorCalibrate(int threshold) {
+  _threshold = threshold;
+  if (threshold > 0 && _num_floor_samples >= NUM_NOISE_FLOOR_SAMPLES) {  // ignore trigger if currently sampling
+    _num_floor_samples = 0;
+    _floor_sample_sum = 0;
+  }
+}
+
+void RadioLibWrapper::loop() {
+  if (state == STATE_RX && _num_floor_samples < NUM_NOISE_FLOOR_SAMPLES) {
+    if (!isReceivingPacket()) {
+      int rssi = getCurrentRSSI();
+      if (rssi < _noise_floor + _threshold) {  // only consider samples below current floor+THRESHOLD
+        _num_floor_samples++;
+        _floor_sample_sum += rssi;
+      }
+    }
+  } else if (_num_floor_samples >= NUM_NOISE_FLOOR_SAMPLES && _floor_sample_sum != 0) {
+    _noise_floor = _floor_sample_sum / NUM_NOISE_FLOOR_SAMPLES;
+    _floor_sample_sum = 0;
+
+    MESH_DEBUG_PRINTLN("RadioLibWrapper: noise_floor = %d", (int)_noise_floor);
+  }
+}
+
 void RadioLibWrapper::startRecv() {
   int err = _radio->startReceive();
   if (err == RADIOLIB_ERR_NONE) {
@@ -108,6 +142,12 @@ void RadioLibWrapper::onSendFinished() {
   state = STATE_IDLE;
 }
 
+bool RadioLibWrapper::isChannelActive() {
+  return _threshold == 0 
+          ? false    // interference check is disabled
+          : getCurrentRSSI() > _noise_floor + _threshold;
+}
+
 float RadioLibWrapper::getLastRSSI() const {
   return _radio->getRSSI();
 }
diff --git a/src/helpers/RadioLibWrappers.h b/src/helpers/RadioLibWrappers.h
index bdbadb19..bb308071 100644
--- a/src/helpers/RadioLibWrappers.h
+++ b/src/helpers/RadioLibWrappers.h
@@ -8,10 +8,14 @@ protected:
   PhysicalLayer* _radio;
   mesh::MainBoard* _board;
   uint32_t n_recv, n_sent;
+  int16_t _noise_floor, _threshold;
+  uint16_t _num_floor_samples;
+  int32_t _floor_sample_sum;
 
   void idle();
   void startRecv();
   float packetScoreInt(float snr, int sf, int packet_len);
+  virtual bool isReceivingPacket() =0;
 
 public:
   RadioLibWrapper(PhysicalLayer& radio, mesh::MainBoard& board) : _radio(&radio), _board(&board) { n_recv = n_sent = 0; }
@@ -23,6 +27,20 @@ public:
   bool isSendComplete() override;
   void onSendFinished() override;
   bool isInRecvMode() const override;
+  bool isChannelActive();
+
+  bool isReceiving() override { 
+    if (isReceivingPacket()) return true;
+
+    return isChannelActive();
+  }
+
+  virtual float getCurrentRSSI() =0;
+
+  int getNoiseFloor() const override { return _noise_floor; }
+  void triggerNoiseFloorCalibrate(int threshold) override;
+
+  void loop() override;
 
   uint32_t getPacketsRecv() const { return n_recv; }
   uint32_t getPacketsSent() const { return n_sent; }
diff --git a/src/helpers/TBeamBoard.h b/src/helpers/TBeamBoard.h
index fc52e712..8eba6933 100644
--- a/src/helpers/TBeamBoard.h
+++ b/src/helpers/TBeamBoard.h
@@ -7,6 +7,9 @@
 
 // Defined using AXP2102
 #define XPOWERS_CHIP_AXP2101
+#define PIN_BOARD_SDA1 42  //SDA for PMU and PFC8563 (RTC)
+#define PIN_BOARD_SCL1 41  //SCL for PMU and PFC8563 (RTC)
+#define PIN_PMU_IRQ 40     //IRQ pin for PMU
 
 // LoRa radio module pins for TBeam
 #define  P_LORA_DIO_0   26
@@ -28,15 +31,13 @@
 #include <driver/rtc_io.h>
 
 class TBeamBoard : public ESP32Board {
-  XPowersAXP2101 power;
-
+  XPowersLibInterface *PMU = NULL;
 public:
+  bool power_init();
+  void printPMU();
+
   void begin() {
     ESP32Board::begin();
-
-    power.setALDO2Voltage(3300);
-    power.enableALDO2();
-
     pinMode(38, INPUT_PULLUP);
 
     esp_reset_reason_t reason = esp_reset_reason();
@@ -49,6 +50,7 @@ public:
       rtc_gpio_hold_dis((gpio_num_t)P_LORA_NSS);
       rtc_gpio_deinit((gpio_num_t)P_LORA_DIO_1);
     }
+    power_init();
   }
 
   void enterDeepSleep(uint32_t secs, int pin_wake_btn = -1) {
@@ -75,7 +77,8 @@ public:
   }
 
   uint16_t getBattMilliVolts() override {
-    return power.getBattVoltage();
+    if(PMU) return PMU->getBattVoltage();
+    else return 0;
   }
 
   const char* getManufacturerName() const override {
diff --git a/src/helpers/TBeamS3SupremeBoard.h b/src/helpers/TBeamS3SupremeBoard.h
index ccb8e24c..47160787 100644
--- a/src/helpers/TBeamS3SupremeBoard.h
+++ b/src/helpers/TBeamS3SupremeBoard.h
@@ -75,6 +75,7 @@ public:
       rtc_gpio_hold_dis((gpio_num_t)P_LORA_NSS);
       rtc_gpio_deinit((gpio_num_t)P_LORA_DIO_1);
     }
+    power_init();
   }
 
   void enterDeepSleep(uint32_t secs, int pin_wake_btn = -1) {
diff --git a/variants/lilygo_tbeam/target.cpp b/variants/lilygo_tbeam/target.cpp
index 116088d6..69a980fc 100644
--- a/variants/lilygo_tbeam/target.cpp
+++ b/variants/lilygo_tbeam/target.cpp
@@ -3,6 +3,14 @@
 
 TBeamBoard board;
 
+// Using PMU AXP2102
+#define PMU_WIRE_PORT               Wire
+
+bool pmuIntFlag = false;
+static void setPMUIntFlag(){
+  pmuIntFlag = true;
+}
+
 #if defined(P_LORA_SCLK)
   static SPIClass spi;
   RADIO_CLASS radio = new Module(P_LORA_NSS, P_LORA_DIO_0, P_LORA_RESET, P_LORA_DIO_1, spi);
@@ -24,6 +32,112 @@ SensorManager sensors;
   #define LORA_CR      5
 #endif
 
+bool TBeamBoard::power_init()
+{
+  if (!PMU)
+  {
+    PMU = new XPowersAXP2101(PMU_WIRE_PORT);
+    if (!PMU->init())
+    {
+      // Serial.println("Warning: Failed to find AXP2101 power management");
+      delete PMU;
+      PMU = NULL;
+    }
+    else
+    {
+      // Serial.println("AXP2101 PMU init succeeded, using AXP2101 PMU");
+    }
+  }
+  if (!PMU)
+  {
+    PMU = new XPowersAXP192(PMU_WIRE_PORT);
+    if (!PMU->init())
+    {
+      // Serial.println("Warning: Failed to find AXP192 power management");
+      delete PMU;
+      PMU = NULL;
+    }
+    else
+    {
+      // Serial.println("AXP192 PMU init succeeded, using AXP192 PMU");
+    }
+  }
+
+  if (!PMU)
+  {
+    MESH_DEBUG_PRINTLN("PMU init failed.");
+    return false;
+  }
+
+  // Serial.printf("PMU  ID:0x%x\n", PMU->getChipID());
+  // printPMU();
+  if (PMU->getChipModel() == XPOWERS_AXP192)
+  {
+    // lora radio power channel
+    PMU->setPowerChannelVoltage(XPOWERS_LDO2, 3300);
+    PMU->enablePowerOutput(XPOWERS_LDO2);
+    // oled module power channel,
+    // disable it will cause abnormal communication between boot and AXP power supply,
+    // do not turn it off
+    PMU->setPowerChannelVoltage(XPOWERS_DCDC1, 3300);
+    // enable oled power
+    PMU->enablePowerOutput(XPOWERS_DCDC1);
+    // gnss module power channel
+    PMU->setPowerChannelVoltage(XPOWERS_LDO3, 3300);
+    // power->enablePowerOutput(XPOWERS_LDO3);
+    // protected oled power source
+    PMU->setProtectedChannel(XPOWERS_DCDC1);
+    // protected esp32 power source
+    PMU->setProtectedChannel(XPOWERS_DCDC3);
+    // disable not use channel
+    PMU->disablePowerOutput(XPOWERS_DCDC2);
+    // disable all axp chip interrupt
+    PMU->disableIRQ(XPOWERS_AXP192_ALL_IRQ);
+    PMU->setChargerConstantCurr(XPOWERS_AXP192_CHG_CUR_550MA);
+  }
+  else if (PMU->getChipModel() == XPOWERS_AXP2101)
+  {
+    // gnss module power channel
+    PMU->setPowerChannelVoltage(XPOWERS_ALDO4, 3300);
+    PMU->enablePowerOutput(XPOWERS_ALDO4);
+    // lora radio power channel
+    PMU->setPowerChannelVoltage(XPOWERS_ALDO3, 3300);
+    PMU->enablePowerOutput(XPOWERS_ALDO3);
+    // m.2 interface
+    PMU->setPowerChannelVoltage(XPOWERS_DCDC3, 3300);
+    PMU->enablePowerOutput(XPOWERS_DCDC3);
+    // power->setPowerChannelVoltage(XPOWERS_DCDC4, 3300);
+    // power->enablePowerOutput(XPOWERS_DCDC4);
+    // not use channel
+    PMU->disablePowerOutput(XPOWERS_DCDC2); // not elicited
+    PMU->disablePowerOutput(XPOWERS_DCDC5); // not elicited
+    PMU->disablePowerOutput(XPOWERS_DLDO1); // Invalid power channel, it does not exist
+    PMU->disablePowerOutput(XPOWERS_DLDO2); // Invalid power channel, it does not exist
+    PMU->disablePowerOutput(XPOWERS_VBACKUP);
+    // disable all axp chip interrupt
+    PMU->disableIRQ(XPOWERS_AXP2101_ALL_IRQ);
+    PMU->setChargerConstantCurr(XPOWERS_AXP2101_CHG_CUR_500MA);
+
+    // Set up PMU interrupts
+    // Serial.println("Setting up PMU interrupts");
+    pinMode(PIN_PMU_IRQ, INPUT_PULLUP);
+    attachInterrupt(PIN_PMU_IRQ, setPMUIntFlag, FALLING);
+
+    // Reset and re-enable PMU interrupts
+    // Serial.println("Re-enable interrupts");
+    PMU->disableIRQ(XPOWERS_AXP2101_ALL_IRQ);
+    PMU->clearIrqStatus();
+    PMU->enableIRQ(
+        XPOWERS_AXP2101_BAT_INSERT_IRQ | XPOWERS_AXP2101_BAT_REMOVE_IRQ |    // Battery interrupts
+        XPOWERS_AXP2101_VBUS_INSERT_IRQ | XPOWERS_AXP2101_VBUS_REMOVE_IRQ |  // VBUS interrupts
+        XPOWERS_AXP2101_PKEY_SHORT_IRQ | XPOWERS_AXP2101_PKEY_LONG_IRQ |     // Power Key interrupts
+        XPOWERS_AXP2101_BAT_CHG_DONE_IRQ | XPOWERS_AXP2101_BAT_CHG_START_IRQ // Charging interrupts
+    );
+  }
+
+  return true;
+}
+
 bool radio_init() {
   fallback_clock.begin();
   rtc_clock.begin(Wire);
@@ -66,3 +180,24 @@ mesh::LocalIdentity radio_new_identity() {
   RadioNoiseListener rng(radio);
   return mesh::LocalIdentity(&rng);  // create new random identity
 }
+
+#ifdef MESH_DEBUG
+void TBeamBoard::printPMU()
+{
+    Serial.print("isCharging:"); Serial.println(PMU->isCharging() ? "YES" : "NO");
+    Serial.print("isDischarge:"); Serial.println(PMU->isDischarge() ? "YES" : "NO");
+    Serial.print("isVbusIn:"); Serial.println(PMU->isVbusIn() ? "YES" : "NO");
+    Serial.print("getBattVoltage:"); Serial.print(PMU->getBattVoltage()); Serial.println("mV");
+    Serial.print("getVbusVoltage:"); Serial.print(PMU->getVbusVoltage()); Serial.println("mV");
+    Serial.print("getSystemVoltage:"); Serial.print(PMU->getSystemVoltage()); Serial.println("mV");
+
+    // The battery percentage may be inaccurate at first use, the PMU will automatically
+    // learn the battery curve and will automatically calibrate the battery percentage
+    // after a charge and discharge cycle
+    if (PMU->isBatteryConnect()) {
+        Serial.print("getBatteryPercent:"); Serial.print(PMU->getBatteryPercent()); Serial.println("%");
+    }
+
+    Serial.println();
+}
+#endif
\ No newline at end of file