Noise floor (#9347)

src/mesh/LR11x0Interface.cpp

@@ -350,4 +350,10 @@ template <typename T> bool LR11x0Interface<T>::sleep()
 
     return true;
 }
+
+template <typename T> int16_t LR11x0Interface<T>::getCurrentRSSI()
+{
+    float rssi = lora.getRSSI();
+    return (int16_t)round(rssi);
+}
 #endif

src/mesh/LR11x0Interface.h

@@ -37,6 +37,8 @@ template <class T> class LR11x0Interface : public RadioLibInterface
      */
     T lora;
 
+    int16_t getCurrentRSSI() override;
+
     /**
      * Glue functions called from ISR land
      */

src/mesh/LR20x0Interface.cpp

@@ -0,0 +1,383 @@
+#include "configuration.h"
+
+#if defined(USE_LR2021) && RADIOLIB_EXCLUDE_LR2021 != 1
+#include "LR20x0Interface.h"
+#include "error.h"
+#include "mesh/NodeDB.h"
+
+// Keep LR20x0 naming while RadioLib exposes LR2021 symbols.
+#ifndef LR20x0
+#define LR20x0 LR2021
+#endif
+
+#ifdef LR2021_DIO_AS_RF_SWITCH
+#include "rfswitch.h"
+#elif ARCH_PORTDUINO
+#include "PortduinoGlue.h"
+#define lr20x0_rfswitch_dio_pins portduino_config.rfswitch_dio_pins
+#define lr20x0_rfswitch_table portduino_config.rfswitch_table
+#else
+static const uint32_t lr20x0_rfswitch_dio_pins[] = {RADIOLIB_NC, RADIOLIB_NC, RADIOLIB_NC, RADIOLIB_NC, RADIOLIB_NC};
+static const Module::RfSwitchMode_t lr20x0_rfswitch_table[] = {
+    {LR20x0::MODE_STBY, {}},  {LR20x0::MODE_RX, {}},    {LR20x0::MODE_TX, {}},
+    {LR20x0::MODE_RX_HF, {}}, {LR20x0::MODE_TX_HF, {}}, END_OF_MODE_TABLE,
+};
+#endif
+
+// Particular boards might define a different max power based on what their hardware can do, default to max power output if not
+// specified (may be dangerous if using external PA and LR20x0 power config forgotten)
+#if ARCH_PORTDUINO
+#define LR2021_MAX_POWER portduino_config.lr2021_max_power
+#endif
+#ifndef LR2021_MAX_POWER
+#define LR2021_MAX_POWER 22
+#endif
+
+// the 2.4G part maxes at 12dBm
+
+#if ARCH_PORTDUINO
+#define LR2021_MAX_POWER_HF portduino_config.lr2021_max_power_hf
+#endif
+#ifndef LR2021_MAX_POWER_HF
+#define LR2021_MAX_POWER_HF 12
+#endif
+
+template <typename T>
+LR20x0Interface<T>::LR20x0Interface(LockingArduinoHal *hal, RADIOLIB_PIN_TYPE cs, RADIOLIB_PIN_TYPE irq, RADIOLIB_PIN_TYPE rst,
+                                    RADIOLIB_PIN_TYPE busy)
+    : RadioLibInterface(hal, cs, irq, rst, busy, &lora), lora(&module)
+{
+    LOG_WARN("LR20x0Interface(cs=%d, irq=%d, rst=%d, busy=%d)", cs, irq, rst, busy);
+}
+
+/// Initialise the Driver transport hardware and software.
+/// Make sure the Driver is properly configured before calling init().
+/// \return true if initialisation succeeded.
+template <typename T> bool LR20x0Interface<T>::init()
+{
+#ifdef LR2021_POWER_EN
+    pinMode(LR2021_POWER_EN, OUTPUT);
+    digitalWrite(LR2021_POWER_EN, HIGH);
+#endif
+
+#if ARCH_PORTDUINO
+    float tcxoVoltage = (float)portduino_config.dio3_tcxo_voltage / 1000;
+// FIXME: correct logic to default to not using TCXO if no voltage is specified for LR20x0_DIO3_TCXO_VOLTAGE
+#elif defined(LR2021_DIO3_TCXO_VOLTAGE)
+    float tcxoVoltage = LR2021_DIO3_TCXO_VOLTAGE;
+    LOG_DEBUG("LR2021_DIO3_TCXO_VOLTAGE defined, using DIO3 as TCXO reference voltage at %f V", LR2021_DIO3_TCXO_VOLTAGE);
+    // (DIO3 is not free to be used as an IRQ)
+#elif defined(TCXO_OPTIONAL)
+    float tcxoVoltage = 1.6f; // TCXO_OPTIONAL: try default 1.6 V first, fall back to XTAL on failure
+    LOG_DEBUG("TCXO_OPTIONAL: no LR2021_DIO3_TCXO_VOLTAGE defined, trying default TCXO Vref 1.6 V first");
+#else
+    float tcxoVoltage =
+        0; // "TCXO reference voltage to be set on DIO3. Defaults to 1.6 V, set to 0 to skip." per
+           // https://github.com/jgromes/RadioLib/blob/690a050ebb46e6097c5d00c371e961c1caa3b52e/src/modules/LR11x0/LR11x0.h#L471C26-L471C104
+    // (DIO3 is free to be used as an IRQ)
+    LOG_DEBUG("LR2021_DIO3_TCXO_VOLTAGE not defined, not using DIO3 as TCXO reference voltage");
+#endif
+
+    RadioLibInterface::init();
+
+#ifdef LR2021_IRQ_DIO_NUM
+    lora.irqDioNum = LR2021_IRQ_DIO_NUM;
+    LOG_DEBUG("Set irqDioNum %d", lora.irqDioNum);
+#elif defined(IRQ_DIO_NUM)
+    lora.irqDioNum = IRQ_DIO_NUM;
+    LOG_DEBUG("Set irqDioNum %d", lora.irqDioNum);
+#else
+    LOG_DEBUG("Use default irqDioNum %d", lora.irqDioNum);
+#endif
+
+    if (config.lora.region == meshtastic_Config_LoRaConfig_RegionCode_LORA_24) { // clamp if wide freq range
+        limitPower(LR2021_MAX_POWER_HF);
+    } else {
+        limitPower(LR2021_MAX_POWER); // default clamp for non-wide freq range
+    }
+
+#ifdef LR2021_RF_SWITCH_SUBGHZ
+    pinMode(LR2021_RF_SWITCH_SUBGHZ, OUTPUT);
+    digitalWrite(LR2021_RF_SWITCH_SUBGHZ, getFreq() < 1e9 ? HIGH : LOW);
+    LOG_DEBUG("Set RF0 switch to %s", getFreq() < 1e9 ? "SubGHz" : "2.4GHz");
+#endif
+
+#ifdef LR2021_RF_SWITCH_2_4GHZ
+    pinMode(LR2021_RF_SWITCH_2_4GHZ, OUTPUT);
+    digitalWrite(LR2021_RF_SWITCH_2_4GHZ, getFreq() < 1e9 ? LOW : HIGH);
+    LOG_DEBUG("Set RF1 switch to %s", getFreq() < 1e9 ? "SubGHz" : "2.4GHz");
+#endif
+
+    // Allow extra time for TCXO to stabilize after power-on
+    delay(10);
+
+    int res = lora.begin(getFreq(), bw, sf, cr, syncWord, power, preambleLength, tcxoVoltage);
+
+    // Retry if we get SPI command failed - some units need extra TCXO stabilization time
+    if (res == RADIOLIB_ERR_SPI_CMD_FAILED) {
+        LOG_WARN("LR20x0 init failed with %d (SPI_CMD_FAILED), retrying after delay...", res);
+        delay(100);
+        res = lora.begin(getFreq(), bw, sf, cr, syncWord, power, preambleLength, tcxoVoltage);
+    }
+
+#if defined(TCXO_OPTIONAL)
+    // If init failed for any reason other than chip not found, retry without TCXO (XTAL mode)
+    if (res != RADIOLIB_ERR_NONE && res != RADIOLIB_ERR_CHIP_NOT_FOUND && tcxoVoltage > 0) {
+        LOG_WARN("LR20x0 init failed with TCXO Vref %f V (err %d), retrying without TCXO", tcxoVoltage, res);
+        tcxoVoltage = 0;
+        res = lora.begin(getFreq(), bw, sf, cr, syncWord, power, preambleLength, tcxoVoltage);
+        if (res == RADIOLIB_ERR_NONE)
+            LOG_INFO("LR20x0 init success without TCXO (XTAL mode)");
+    }
+#endif
+
+    // \todo Display actual typename of the adapter, not just `LR20x0`
+    LOG_INFO("LR20x0 init result %d", res);
+    if (res == RADIOLIB_ERR_CHIP_NOT_FOUND || res == RADIOLIB_ERR_SPI_CMD_FAILED)
+        return false;
+
+    LOG_INFO("Frequency set to %f", getFreq());
+    LOG_INFO("Bandwidth set to %f", bw);
+    LOG_INFO("Power output set to %d", power);
+
+    if (res == RADIOLIB_ERR_NONE)
+        res = lora.setCRC(2);
+
+#ifdef LR2021_DIO_AS_RF_SWITCH
+    bool dioAsRfSwitch = true;
+#elif defined(ARCH_PORTDUINO)
+    bool dioAsRfSwitch = portduino_config.has_rfswitch_table;
+#else
+    bool dioAsRfSwitch = false;
+#endif
+
+    if (dioAsRfSwitch) {
+        lora.setRfSwitchTable(lr20x0_rfswitch_dio_pins, lr20x0_rfswitch_table);
+        LOG_DEBUG("Set DIO RF switch");
+    }
+
+    if (res == RADIOLIB_ERR_NONE) {
+        if (config.lora.sx126x_rx_boosted_gain) { // the name is unfortunate but historically accurate
+            res = lora.setRxBoostedGainMode(true);
+            LOG_INFO("Set RX gain to boosted mode; result: %d", res);
+        } else {
+            res = lora.setRxBoostedGainMode(false);
+            LOG_INFO("Set RX gain to power saving mode (boosted mode off); result: %d", res);
+        }
+    }
+
+    if (res == RADIOLIB_ERR_NONE)
+        startReceive(); // start receiving
+
+    return res == RADIOLIB_ERR_NONE;
+}
+
+template <typename T> bool LR20x0Interface<T>::reconfigure()
+{
+    RadioLibInterface::reconfigure();
+
+    // set mode to standby
+    setStandby();
+
+    // configure publicly accessible settings
+    int err = lora.setSpreadingFactor(sf);
+    if (err != RADIOLIB_ERR_NONE)
+        RECORD_CRITICALERROR(meshtastic_CriticalErrorCode_INVALID_RADIO_SETTING);
+
+    err = lora.setBandwidth(bw); // different form than LR11xx
+    if (err != RADIOLIB_ERR_NONE)
+        RECORD_CRITICALERROR(meshtastic_CriticalErrorCode_INVALID_RADIO_SETTING);
+
+    err = lora.setCodingRate(cr, cr != 7); // use long interleaving except if CR is 4/7 which doesn't support it
+    if (err != RADIOLIB_ERR_NONE)
+        RECORD_CRITICALERROR(meshtastic_CriticalErrorCode_INVALID_RADIO_SETTING);
+
+    err = lora.setSyncWord(syncWord);
+    assert(err == RADIOLIB_ERR_NONE);
+
+    if (config.lora.region == meshtastic_Config_LoRaConfig_RegionCode_LORA_24) { // clamp if wide freq range
+        limitPower(LR2021_MAX_POWER_HF);
+    } else {
+        limitPower(LR2021_MAX_POWER); // default clamp for non-wide freq range
+    }
+
+    err = lora.setPreambleLength(preambleLength);
+    assert(err == RADIOLIB_ERR_NONE);
+
+    err = lora.setFrequency(getFreq());
+    if (err != RADIOLIB_ERR_NONE)
+        RECORD_CRITICALERROR(meshtastic_CriticalErrorCode_INVALID_RADIO_SETTING);
+
+    err = lora.setOutputPower(power);
+    assert(err == RADIOLIB_ERR_NONE);
+
+    // Apply RX gain mode — valid in STDBY, matches resetAGC() pattern
+    err = lora.setRxBoostedGainMode(config.lora.sx126x_rx_boosted_gain);
+    if (err != RADIOLIB_ERR_NONE)
+        LOG_WARN("LR20x0 setRxBoostedGainMode %s%d", radioLibErr, err);
+
+    startReceive(); // restart receiving
+
+    return true;
+}
+
+template <typename T> void LR20x0Interface<T>::disableInterrupt()
+{
+    lora.clearIrqAction();
+}
+
+template <typename T> void LR20x0Interface<T>::setStandby()
+{
+    checkNotification(); // handle any pending interrupts before we force standby
+
+    int err = lora.standby();
+
+    if (err != RADIOLIB_ERR_NONE) {
+        LOG_DEBUG("LR20x0 standby failed with error %d", err);
+    }
+
+    assert(err == RADIOLIB_ERR_NONE);
+
+    isReceiving = false; // If we were receiving, not any more
+    activeReceiveStart = 0;
+    disableInterrupt();
+    completeSending(); // If we were sending, not anymore
+    RadioLibInterface::setStandby();
+}
+
+/**
+ * Add SNR data to received messages
+ */
+template <typename T> void LR20x0Interface<T>::addReceiveMetadata(meshtastic_MeshPacket *mp)
+{
+    // LOG_DEBUG("PacketStatus %x", lora.getPacketStatus());
+    mp->rx_snr = lora.getSNR();
+    mp->rx_rssi = lround(lora.getRSSI());
+    // LOG_DEBUG("Corrected frequency offset: %f", lora.getFrequencyError()); // not implemented for LR20x0, but noop for LR11x0
+    // too(!)
+}
+
+/** We override to turn on transmitter power as needed.
+ */
+template <typename T> void LR20x0Interface<T>::configHardwareForSend()
+{
+    RadioLibInterface::configHardwareForSend();
+}
+
+// For power draw measurements, helpful to force radio to stay sleeping
+// #define SLEEP_ONLY
+
+template <typename T> void LR20x0Interface<T>::startReceive()
+{
+#ifdef SLEEP_ONLY
+    sleep();
+#else
+
+    setStandby();
+
+    lora.setPreambleLength(preambleLength); // Solve RX ack fail after direct message sent.  Not sure why this is needed.
+
+    // We use a 16 bit preamble so this should save some power by letting radio sit in standby mostly.
+    int err =
+        lora.startReceive(RADIOLIB_LR2021_RX_TIMEOUT_INF, MESHTASTIC_RADIOLIB_IRQ_RX_FLAGS, RADIOLIB_IRQ_RX_DEFAULT_MASK, 0);
+    if (err)
+        LOG_ERROR("StartReceive error: %d", err);
+    assert(err == RADIOLIB_ERR_NONE);
+
+    RadioLibInterface::startReceive();
+
+    // Must be done AFTER starting receive, because startReceive clears (possibly stale) interrupt pending register bits
+    enableInterrupt(isrRxLevel0);
+    checkRxDoneIrqFlag();
+#endif
+}
+
+/** Is the channel currently active? */
+template <typename T> bool LR20x0Interface<T>::isChannelActive()
+{
+    // check if we can detect a LoRa preamble on the current channel
+    ChannelScanConfig_t cfg = {.cad = {.symNum = NUM_SYM_CAD,
+                                       .detPeak = RADIOLIB_LR2021_CAD_PARAM_DEFAULT,
+                                       .detMin = RADIOLIB_LR2021_CAD_PARAM_DEFAULT,
+                                       .exitMode = RADIOLIB_LR2021_CAD_PARAM_DEFAULT,
+                                       .timeout = 0,
+                                       .irqFlags = RADIOLIB_IRQ_CAD_DEFAULT_FLAGS,
+                                       .irqMask = RADIOLIB_IRQ_CAD_DEFAULT_MASK}};
+    int16_t result;
+
+    setStandby();
+    result = lora.scanChannel(cfg);
+    if (result == RADIOLIB_LORA_DETECTED)
+        return true;
+
+    assert(result != RADIOLIB_ERR_WRONG_MODEM);
+
+    return false;
+}
+
+/** Could we send right now (i.e. either not actively receiving or transmitting)? */
+template <typename T> bool LR20x0Interface<T>::isActivelyReceiving()
+{
+    // The IRQ status will be cleared when we start our read operation. Check if we've started a header, but haven't yet
+    // received and handled the interrupt for reading the packet/handling errors.
+    return receiveDetected(lora.getIrqStatus(), RADIOLIB_LR2021_IRQ_LORA_HEADER_VALID, RADIOLIB_LR2021_IRQ_PREAMBLE_DETECTED);
+}
+
+#ifdef LR20X0_AGC_RESET
+template <typename T> void LR20x0Interface<T>::resetAGC()
+{
+    // Safety: don't reset mid-packet
+    if (sendingPacket != NULL || (isReceiving && isActivelyReceiving()))
+        return;
+
+    LOG_DEBUG("LR20x0 AGC reset: warm sleep + Calibrate(0x3F)");
+
+    // 1. Warm sleep — powers down the analog frontend, resetting AGC state
+    lora.sleep(true, 0);
+
+    // 2. Wake to RC standby for stable calibration
+    lora.standby(RADIOLIB_LR20X0_STANDBY_RC, true);
+
+    // 3. Calibrate all blocks (PLL, ADC, image, RC oscillators)
+    //    calibrate() is protected on LR20x0, so use raw SPI (same as internal implementation)
+    uint8_t calData = RADIOLIB_LR20X0_CALIBRATE_ALL;
+    module.SPIwriteStream(RADIOLIB_LR20X0_CMD_CALIBRATE, &calData, 1, true, true);
+
+    // 4. Re-calibrate image rejection for actual operating frequency
+    //    Calibrate(0x3F) defaults to 902-928 MHz which is wrong for other regions.
+    lora.calibrateImageRejection(getFreq() - 4.0f, getFreq() + 4.0f);
+
+    // 5. Re-apply RX boosted gain mode
+    lora.setRxBoostedGainMode(config.lora.sx126x_rx_boosted_gain);
+
+    // 6. Resume receiving
+    startReceive();
+}
+#endif
+
+template <typename T> bool LR20x0Interface<T>::sleep()
+{
+    // \todo Display actual typename of the adapter, not just `LR20x0`
+    LOG_DEBUG("LR20x0 entering sleep mode");
+    setStandby(); // Stop any pending operations
+
+    // turn off TCXO if it was powered
+    lora.setTCXO(0);
+
+    // put chipset into sleep mode (we've already disabled interrupts by now)
+    bool keepConfig = false;
+    lora.sleep(keepConfig, 0); // Note: we do not keep the config, full reinit will be needed
+
+#ifdef LR2021_POWER_EN
+    digitalWrite(LR2021_POWER_EN, LOW);
+#endif
+
+    return true;
+}
+
+template <typename T> int16_t LR20x0Interface<T>::getCurrentRSSI()
+{
+    float rssi = lora.getRSSI();
+    return (int16_t)round(rssi);
+}
+#endif

src/mesh/LR20x0Interface.h

@@ -0,0 +1,77 @@
+#pragma once
+#if RADIOLIB_EXCLUDE_LR2021 != 1
+#include "RadioLibInterface.h"
+
+/**
+ * \brief Adapter for LR20x0 radio family. Implements common logic for child classes.
+ * \tparam T RadioLib module type for LR20x0, e.g. LR2021.
+ */
+template <class T> class LR20x0Interface : public RadioLibInterface
+{
+  public:
+    LR20x0Interface(LockingArduinoHal *hal, RADIOLIB_PIN_TYPE cs, RADIOLIB_PIN_TYPE irq, RADIOLIB_PIN_TYPE rst,
+                    RADIOLIB_PIN_TYPE busy);
+
+    /// Initialise the Driver transport hardware and software.
+    /// Make sure the Driver is properly configured before calling init().
+    /// \return true if initialisation succeeded.
+    virtual bool init() override;
+
+    /// Apply any radio provisioning changes
+    /// Make sure the Driver is properly configured before calling init().
+    /// \return true if initialisation succeeded.
+    virtual bool reconfigure() override;
+
+    /// Prepare hardware for sleep.  Call this _only_ for deep sleep, not needed for light sleep.
+    virtual bool sleep() override;
+
+    bool isIRQPending() override { return lora.getIrqFlags() != 0; }
+
+#ifdef LR20X0_AGC_RESET
+    void resetAGC() override;
+#endif
+
+  protected:
+    /**
+     * Specific module instance
+     */
+    T lora;
+
+    int16_t getCurrentRSSI() override;
+
+    /**
+     * Glue functions called from ISR land
+     */
+    virtual void disableInterrupt() override;
+
+    /**
+     * Enable a particular ISR callback glue function
+     */
+    virtual void enableInterrupt(void (*callback)()) { lora.setIrqAction(callback); }
+
+    /** can we detect a LoRa preamble on the current channel? */
+    virtual bool isChannelActive() override;
+
+    /** are we actively receiving a packet (only called during receiving state) */
+    virtual bool isActivelyReceiving() override;
+
+    /**
+     * Start waiting to receive a message
+     */
+    virtual void startReceive() override;
+
+    /**
+     *  We override to turn on transmitter power as needed.
+     */
+    virtual void configHardwareForSend() override;
+
+    /**
+     * Add SNR data to received messages
+     */
+    virtual void addReceiveMetadata(meshtastic_MeshPacket *mp) override;
+
+    virtual void setStandby() override;
+
+    uint32_t getPacketTime(uint32_t pl, bool received) override { return computePacketTime(lora, pl, received); }
+};
+#endif

src/mesh/RF95Interface.cpp

@@ -342,4 +342,10 @@ bool RF95Interface::sleep()
 
     return true;
 }
+
+int16_t RF95Interface::getCurrentRSSI()
+{
+    float rssi = lora->getRSSI(false);
+    return (int16_t)round(rssi);
+}
 #endif

src/mesh/RF95Interface.h

@@ -37,6 +37,8 @@ class RF95Interface : public RadioLibInterface
      */
     virtual void disableInterrupt() override;
 
+    int16_t getCurrentRSSI() override;
+
     /**
      * Enable a particular ISR callback glue function
      */

src/mesh/RadioInterface.h

@@ -264,6 +264,12 @@ class RadioInterface
      */
     virtual void saveChannelNum(uint32_t savedChannelNum);
 
+    /**
+     * Get current RSSI reading from the radio.
+     * Returns 0 if not available.
+     */
+    virtual int16_t getCurrentRSSI() { return 0; }
+
   private:
     /**
      * Convert our modemConfig enum into wf, sf, etc...

src/mesh/RadioLibInterface.cpp

@@ -15,6 +15,7 @@
 #include "PortduinoGlue.h"
 #include "meshUtils.h"
 #endif
+
 void LockingArduinoHal::spiBeginTransaction()
 {
     spiLock->lock();
@@ -28,6 +29,7 @@ void LockingArduinoHal::spiEndTransaction()
 
     spiLock->unlock();
 }
+
 #if ARCH_PORTDUINO
 void LockingArduinoHal::spiTransfer(uint8_t *out, size_t len, uint8_t *in)
 {
@@ -40,6 +42,12 @@ RadioLibInterface::RadioLibInterface(LockingArduinoHal *hal, RADIOLIB_PIN_TYPE c
     : NotifiedWorkerThread("RadioIf"), module(hal, cs, irq, rst, busy), iface(_iface)
 {
     instance = this;
+
+    // Initialize unused sample slots to a sane default; sample count controls averaging.
+    for (uint8_t i = 0; i < NOISE_FLOOR_SAMPLES; i++) {
+        noiseFloorSamples[i] = NOISE_FLOOR_DEFAULT;
+    }
+
 #if defined(ARCH_STM32WL) && defined(USE_SX1262)
     module.setCb_digitalWrite(stm32wl_emulate_digitalWrite);
     module.setCb_digitalRead(stm32wl_emulate_digitalRead);
@@ -246,6 +254,87 @@ bool RadioLibInterface::findInTxQueue(NodeNum from, PacketId id)
     return txQueue.find(from, id);
 }
 
+void RadioLibInterface::updateNoiseFloor()
+{
+    // Only sample from idle receive mode. TX/RX-critical paths must return to radio work quickly.
+    if (!isReceiving || sendingPacket != NULL || isActivelyReceiving() || isIRQPending()) {
+        return;
+    }
+
+    uint32_t now = millis();
+    if (now - lastNoiseFloorUpdate < NOISE_FLOOR_UPDATE_INTERVAL_MS) {
+        return;
+    }
+    lastNoiseFloorUpdate = now;
+
+    int16_t rssi = getCurrentRSSI();
+    if (rssi == NOISE_FLOOR_INVALID || rssi >= 0 || rssi < NOISE_FLOOR_VALID_MIN) {
+        LOG_DEBUG("Skipping invalid RSSI reading: %d", rssi);
+        return;
+    }
+
+    noiseFloorSamples[currentSampleIndex] = (int32_t)rssi;
+    currentSampleIndex++;
+
+    if (currentSampleIndex >= NOISE_FLOOR_SAMPLES) {
+        currentSampleIndex = 0;
+        isNoiseFloorBufferFull = true;
+    }
+
+    currentNoiseFloor = getAverageNoiseFloorInternal();
+
+    LOG_DEBUG("Noise floor: %d dBm (samples: %d, latest: %d dBm)", currentNoiseFloor, getNoiseFloorSampleCountInternal(), rssi);
+}
+
+uint8_t RadioLibInterface::getNoiseFloorSampleCountInternal() const
+{
+    return isNoiseFloorBufferFull ? NOISE_FLOOR_SAMPLES : currentSampleIndex;
+}
+
+int32_t RadioLibInterface::getAverageNoiseFloorInternal() const
+{
+    uint8_t sampleCount = getNoiseFloorSampleCountInternal();
+
+    if (sampleCount == 0) {
+        return NOISE_FLOOR_DEFAULT;
+    }
+
+    int32_t sum = 0;
+    for (uint8_t i = 0; i < sampleCount; i++) {
+        sum += noiseFloorSamples[i];
+    }
+
+    return sum / sampleCount;
+}
+
+int32_t RadioLibInterface::getAverageNoiseFloor()
+{
+    return getAverageNoiseFloorInternal();
+}
+
+int32_t RadioLibInterface::getNoiseFloor()
+{
+    return currentNoiseFloor;
+}
+
+bool RadioLibInterface::hasNoiseFloorSamples()
+{
+    return getNoiseFloorSampleCountInternal() > 0;
+}
+
+uint8_t RadioLibInterface::getNoiseFloorSampleCount()
+{
+    return getNoiseFloorSampleCountInternal();
+}
+
+void RadioLibInterface::resetNoiseFloor()
+{
+    currentSampleIndex = 0;
+    isNoiseFloorBufferFull = false;
+    currentNoiseFloor = NOISE_FLOOR_DEFAULT;
+    LOG_INFO("Noise floor reset - rolling window collection will restart");
+}
+
 bool RadioLibInterface::randomBytes(uint8_t *buffer, size_t length)
 {
     if (!buffer || length == 0 || !iface) {
@@ -273,6 +362,7 @@ currently active.
 */
 void RadioLibInterface::onNotify(uint32_t notification)
 {
+
     switch (notification) {
     case ISR_TX:
         handleTransmitInterrupt();
@@ -404,11 +494,6 @@ bool RadioLibInterface::removePendingTXPacket(NodeNum from, PacketId id, uint32_
     return false;
 }
 
-/**
- * Remove a packet that is eligible for replacement from the TX queue
- */
-// void RadioLibInterface::removePending
-
 void RadioLibInterface::handleTransmitInterrupt()
 {
     // This can be null if we forced the device to enter standby mode.  In that case

src/mesh/RadioLibInterface.h

@@ -99,11 +99,42 @@ class RadioLibInterface : public RadioInterface, protected concurrency::Notified
     /// are _trying_ to receive a packet currently (note - we might just be waiting for one)
     bool isReceiving = false;
 
+  protected:
+    // Noise floor tracking - rolling window of samples.
+    static const uint8_t NOISE_FLOOR_SAMPLES = 20;
+    static const int32_t NOISE_FLOOR_DEFAULT = -120;
+    static const int32_t NOISE_FLOOR_VALID_MIN = -127;
+    static const int32_t NOISE_FLOOR_INVALID = -128;
+    int32_t noiseFloorSamples[NOISE_FLOOR_SAMPLES];
+    uint8_t currentSampleIndex = 0;
+    bool isNoiseFloorBufferFull = false;
+    uint32_t lastNoiseFloorUpdate = 0;
+    static const uint32_t NOISE_FLOOR_UPDATE_INTERVAL_MS = 5000;
+    int32_t currentNoiseFloor = NOISE_FLOOR_DEFAULT;
+
+    /**
+     * Pure virtual hook for derived radio interfaces to provide instantaneous RSSI.
+     * Implementations should return dBm, or an invalid value that updateNoiseFloor()
+     * can reject.
+     */
+    virtual int16_t getCurrentRSSI() = 0;
+
   public:
     /** Our ISR code currently needs this to find our active instance
      */
     static RadioLibInterface *instance;
 
+    /**
+     * Get the current calculated noise floor in dBm
+     * Returns -120 dBm if not yet calibrated
+     */
+    int32_t getNoiseFloor();
+
+    /**
+     * Calculate the average noise floor from collected samples
+     */
+    int32_t getAverageNoiseFloor();
+
     /**
      * Glue functions called from ISR land
      */
@@ -172,6 +203,28 @@ class RadioLibInterface : public RadioInterface, protected concurrency::Notified
     /** Attempt to find a packet in the TxQueue. Returns true if the packet was found. */
     virtual bool findInTxQueue(NodeNum from, PacketId id) override;
 
+    /**
+     * Update the noise floor measurement by sampling RSSI from a slow path.
+     * This should not be called from radio interrupt or TX/RX critical paths.
+     */
+    void updateNoiseFloor();
+
+    /**
+     * Check if we have collected any noise floor samples
+     */
+    bool hasNoiseFloorSamples();
+
+    /**
+     * Get the number of samples in the rolling window
+     */
+    uint8_t getNoiseFloorSampleCount();
+
+    /**
+     * Reset the noise floor calibration
+     * Will automatically restart collection
+     */
+    void resetNoiseFloor();
+
     /**
      * Request randomness sourced from the LoRa modem, if supported by the active RadioLib interface.
      * @return true if len bytes were produced, false otherwise.
@@ -179,6 +232,9 @@ class RadioLibInterface : public RadioInterface, protected concurrency::Notified
     bool randomBytes(uint8_t *buffer, size_t length);
 
   private:
+    uint8_t getNoiseFloorSampleCountInternal() const;
+    int32_t getAverageNoiseFloorInternal() const;
+
     /** if we have something waiting to send, start a short (random) timer so we can come check for collision before actually
      * doing the transmit */
     void setTransmitDelay();

src/mesh/SX126xInterface.cpp

@@ -258,6 +258,12 @@ template <typename T> bool SX126xInterface<T>::reconfigure()
     return RADIOLIB_ERR_NONE;
 }
 
+template <typename T> int16_t SX126xInterface<T>::getCurrentRSSI()
+{
+    float rssi = lora.getRSSI(false);
+    return (int16_t)round(rssi);
+}
+
 template <typename T> void SX126xInterface<T>::disableInterrupt()
 {
     lora.clearDio1Action();

src/mesh/SX126xInterface.h

@@ -41,6 +41,8 @@ template <class T> class SX126xInterface : public RadioLibInterface
      */
     T lora;
 
+    int16_t getCurrentRSSI() override;
+
     /**
      * Glue functions called from ISR land
      */

src/mesh/SX128xInterface.cpp

@@ -326,4 +326,10 @@ template <typename T> bool SX128xInterface<T>::sleep()
 
     return true;
 }
+
+template <typename T> int16_t SX128xInterface<T>::getCurrentRSSI()
+{
+    float rssi = lora.getRSSI(false);
+    return (int16_t)round(rssi);
+}
 #endif

src/mesh/SX128xInterface.h

@@ -35,6 +35,8 @@ template <class T> class SX128xInterface : public RadioLibInterface
      */
     T lora;
 
+    int16_t getCurrentRSSI() override;
+
     /**
      * Glue functions called from ISR land
      */

src/modules/Telemetry/DeviceTelemetry.cpp

@@ -20,6 +20,7 @@ static constexpr uint16_t TX_HISTORY_KEY_DEVICE_TELEMETRY = 0x8001;
 
 int32_t DeviceTelemetryModule::runOnce()
 {
+
     refreshUptime();
     uint32_t lastTelemetry = transmitHistory ? transmitHistory->getLastSentToMeshMillis(TX_HISTORY_KEY_DEVICE_TELEMETRY) : 0;
     bool isImpoliteRole = isSensorOrRouterRole();
@@ -125,6 +126,8 @@ meshtastic_Telemetry DeviceTelemetryModule::getLocalStatsTelemetry()
     telemetry.variant.local_stats.num_online_nodes = numOnlineNodes;
     telemetry.variant.local_stats.num_total_nodes = nodeDB->getNumMeshNodes();
     if (RadioLibInterface::instance) {
+        RadioLibInterface::instance->updateNoiseFloor();
+        telemetry.variant.local_stats.noise_floor = RadioLibInterface::instance->getAverageNoiseFloor();
         telemetry.variant.local_stats.num_packets_tx = RadioLibInterface::instance->txGood;
         telemetry.variant.local_stats.num_packets_rx = RadioLibInterface::instance->rxGood + RadioLibInterface::instance->rxBad;
         telemetry.variant.local_stats.num_packets_rx_bad = RadioLibInterface::instance->rxBad;
@@ -133,6 +136,8 @@ meshtastic_Telemetry DeviceTelemetryModule::getLocalStatsTelemetry()
     }
 #ifdef ARCH_PORTDUINO
     if (SimRadio::instance) {
+        if (!RadioLibInterface::instance)
+            telemetry.variant.local_stats.noise_floor = SimRadio::instance->getCurrentRSSI();
         telemetry.variant.local_stats.num_packets_tx = SimRadio::instance->txGood;
         telemetry.variant.local_stats.num_packets_rx = SimRadio::instance->rxGood + SimRadio::instance->rxBad;
         telemetry.variant.local_stats.num_packets_rx_bad = SimRadio::instance->rxBad;
@@ -148,10 +153,11 @@ meshtastic_Telemetry DeviceTelemetryModule::getLocalStatsTelemetry()
         telemetry.variant.local_stats.num_tx_relay_canceled = router->txRelayCanceled;
     }
 
-    LOG_INFO("Sending local stats: uptime=%i, channel_utilization=%f, air_util_tx=%f, num_online_nodes=%i, num_total_nodes=%i",
+    LOG_INFO("Sending local stats: uptime=%i, channel_utilization=%f, air_util_tx=%f, num_online_nodes=%i, num_total_nodes=%i, "
+             "noise_floor=%d",
              telemetry.variant.local_stats.uptime_seconds, telemetry.variant.local_stats.channel_utilization,
              telemetry.variant.local_stats.air_util_tx, telemetry.variant.local_stats.num_online_nodes,
-             telemetry.variant.local_stats.num_total_nodes);
+             telemetry.variant.local_stats.num_total_nodes, telemetry.variant.local_stats.noise_floor);
 
     LOG_INFO("num_packets_tx=%i, num_packets_rx=%i, num_packets_rx_bad=%i", telemetry.variant.local_stats.num_packets_tx,
              telemetry.variant.local_stats.num_packets_rx, telemetry.variant.local_stats.num_packets_rx_bad);
@@ -194,4 +200,4 @@ bool DeviceTelemetryModule::sendTelemetry(NodeNum dest, bool phoneOnly)
         service->sendToMesh(p, RX_SRC_LOCAL, true);
     }
     return true;
-}
+}

src/platform/portduino/SimRadio.cpp

@@ -362,4 +362,10 @@ uint32_t SimRadio::getPacketTime(uint32_t pl, bool received)
 
     uint32_t msecs = tPacket * 1000;
     return msecs;
+}
+
+int16_t SimRadio::getCurrentRSSI()
+{
+    // Simulated radio - return a reasonable default noise floor
+    return -120;
 }

src/platform/portduino/SimRadio.h

@@ -48,6 +48,8 @@ class SimRadio : public RadioInterface, protected concurrency::NotifiedWorkerThr
     // Convert Compressed_msg to normal msg and receive it
     void unpackAndReceive(meshtastic_MeshPacket &p);
 
+    int16_t getCurrentRSSI() override;
+
     /**
      * Debugging counts
      */
@@ -93,4 +95,4 @@ class SimRadio : public RadioInterface, protected concurrency::NotifiedWorkerThr
     virtual uint32_t getPacketTime(uint32_t pl, bool received = false) override;
 };
 
-extern SimRadio *simRadio;
+extern SimRadio *simRadio;