about update

README.md

@@ -51,6 +51,7 @@ ____________________________________________________
 <br />
 
 # Timeline (Versions):
+- 2026-06-10 CAD (Channel Activity Detection) and DIFS (Distributed Inter-Frame Space) added.
 - 2026-03-25 More Boards, SDK update, OTA fix, GPS process update.
 - 2026-02-26 9M2IBR ESP32 1W (400M30S) + GPS board added.
 - 2026-02-25 Code Improvements: reduced String comparisons and improved logic for faster code execution.

common_settings.ini

@@ -32,16 +32,16 @@ lib_deps =
 	adafruit/Adafruit Si7021 Library @ 1.5.3
 	arduino-libraries/NTPClient @ 3.2.1
 	ayushsharma82/ElegantOTA @ 3.1.7
-	bblanchon/ArduinoJson @ 7.4.2
+	bblanchon/ArduinoJson @ 7.4.3
 	jgromes/RadioLib @ 7.6.0
 	knolleary/PubSubClient @ 2.8
 	ESP32Async/AsyncTCP @ 3.4.10
-	ESP32Async/ESPAsyncWebServer @ 3.10.0
+	ESP32Async/ESPAsyncWebServer @ 3.11.1
 	mikalhart/TinyGPSPlus @ 1.0.3
 	richonguzman/APRSPacketLib @ 1.0.4
 display_libs =
-	adafruit/Adafruit GFX Library @ 1.11.9
-	adafruit/Adafruit SSD1306 @ 2.5.10
+	adafruit/Adafruit GFX Library @ 1.12.6
+	adafruit/Adafruit SSD1306 @ 2.5.17
 usb_flags=
 	-DARDUINO_USB_MODE=1
 	-DARDUINO_USB_CDC_ON_BOOT=1

data/igate_conf.json

@@ -28,9 +28,9 @@
         "messagesToRF": false,
         "objectsToRF": false,
         "server": "rotate.aprs2.net",
-        "passcode": "XYZVW",        
+        "passcode": "XYZVW",
         "port": 14580,
-        "filter": "m/10"        
+        "filter": "m/10"
     },
     "personalNote": "",
     "blacklist": "",
@@ -47,10 +47,11 @@
         "rxSignalBandwidth": 125000,
         "txActive": false,
         "txFreq": 433775000,
-        "txSpreadingFactor": 12,
-        "txCodingRate4": 5,
+        "txSpreadingFactor": 9,
+        "txCodingRate4": 7,
         "txSignalBandwidth": 125000,
-        "power": 20
+        "power": 20,
+        "cadActive": true
     },
     "display": {
         "alwaysOn": true,

data_embed/script.js

@@ -118,7 +118,7 @@ function loadSettings(settings) {
     document.getElementById("beacon.latitude").value                    = settings.beacon.latitude;
     document.getElementById("beacon.longitude").value                   = settings.beacon.longitude;
     document.getElementById("beacon.interval").value                    = settings.beacon.interval;
-    document.getElementById("other.rememberStationTime").value          = settings.other.rememberStationTime;   
+    document.getElementById("other.rememberStationTime").value          = settings.other.rememberStationTime;
     document.getElementById("beacon.sendViaAPRSIS").checked             = settings.beacon.sendViaAPRSIS;
 
     document.getElementById("beacon.sendViaRF").checked                 = settings.beacon.sendViaRF;
@@ -148,12 +148,26 @@ function loadSettings(settings) {
     document.getElementById("lora.rxSpreadingFactor").value             = settings.lora.rxSpreadingFactor;
     document.getElementById("lora.rxCodingRate4").value                 = settings.lora.rxCodingRate4;
     document.getElementById("lora.rxSignalBandwidth").value             = settings.lora.rxSignalBandwidth;
+    LoRaRxCheckbox.checked = settings.lora.rxActive;
+    LoRaRxFreq.disabled             = !LoRaRxCheckbox.checked;
+    LoRaRxSpreadingFactor.disabled  = !LoRaRxCheckbox.checked;
+    LoRaRxCodingRate.disabled       = !LoRaRxCheckbox.checked;
+    LoRaRxSignalBandwidth.disabled  = !LoRaRxCheckbox.checked;
+
     document.getElementById("lora.txActive").checked                    = settings.lora.txActive;
     document.getElementById("lora.txFreq").value                        = settings.lora.txFreq;
     document.getElementById("lora.txSpreadingFactor").value             = settings.lora.txSpreadingFactor;
     document.getElementById("lora.txCodingRate4").value                 = settings.lora.txCodingRate4;
-    document.getElementById("lora.txSignalBandwidth").value             = settings.lora.txSignalBandwidth;    
+    document.getElementById("lora.txSignalBandwidth").value             = settings.lora.txSignalBandwidth;
     document.getElementById("lora.power").value                         = settings.lora.power;
+    document.getElementById("lora.cadActive").checked                   = settings.lora.cadActive;
+    LoRaTxCheckbox.checked = settings.lora.txActive;
+    LoRaTxFreq.disabled             = !LoRaTxCheckbox.checked;
+    LoRaTxSpreadingFactor.disabled  = !LoRaTxCheckbox.checked;
+    LoRaTxCodingRate.disabled       = !LoRaTxCheckbox.checked;
+    LoRaTxSignalBandwidth.disabled  = !LoRaTxCheckbox.checked;
+    LoRaPower.disabled              = !LoRaTxCheckbox.checked;
+    LoRaCadActive.disabled          = !LoRaTxCheckbox.checked;
 
     // Display
     document.getElementById("display.alwaysOn").checked                 = settings.display.alwaysOn;
@@ -195,7 +209,7 @@ function loadSettings(settings) {
     TelemetryCheckbox.checked           = settings.wxsensor.active;
     TelemetryHeightCorrection.disabled  = !TelemetryCheckbox.checked;
     TelemetryTempCorrection.disabled    = !TelemetryCheckbox.checked;
-    
+
     // SYSLOG
     document.getElementById("syslog.active").checked                    = settings.syslog.active;
     document.getElementById("syslog.server").value                      = settings.syslog.server;
@@ -205,7 +219,7 @@ function loadSettings(settings) {
     SyslogServer.disabled           = !SyslogCheckbox.checked;
     SyslogPort.disabled             = !SyslogCheckbox.checked;
     SyslogBeaconOverTCPIP.disabled  = !SyslogCheckbox.checked;
-    
+
     // TNC
     if (settings.tnc) {
         document.getElementById("tnc.enableServer").checked             = settings.tnc.enableServer;
@@ -390,6 +404,36 @@ TelemetryCheckbox.addEventListener("change", function () {
     TelemetryTempCorrection.disabled    = !this.checked;
 });
 
+// LoRa Rx Switch
+const LoRaRxCheckbox                = document.querySelector('input[name="lora.rxActive"]');
+const LoRaRxFreq                    = document.querySelector('[name="lora.rxFreq"]');
+const LoRaRxSpreadingFactor         = document.querySelector('[name="lora.rxSpreadingFactor"]');
+const LoRaRxCodingRate              = document.querySelector('[name="lora.rxCodingRate4"]');
+const LoRaRxSignalBandwidth         = document.querySelector('[name="lora.rxSignalBandwidth"]');
+LoRaRxCheckbox.addEventListener("change", function () {
+    LoRaRxFreq.disabled             = !this.checked;
+    LoRaRxSpreadingFactor.disabled  = !this.checked;
+    LoRaRxCodingRate.disabled       = !this.checked;
+    LoRaRxSignalBandwidth.disabled  = !this.checked;
+});
+
+// LoRa Tx Switch
+const LoRaTxCheckbox                = document.querySelector('input[name="lora.txActive"]');
+const LoRaTxFreq                    = document.querySelector('[name="lora.txFreq"]');
+const LoRaTxSpreadingFactor         = document.querySelector('[name="lora.txSpreadingFactor"]');
+const LoRaTxCodingRate              = document.querySelector('[name="lora.txCodingRate4"]');
+const LoRaTxSignalBandwidth         = document.querySelector('[name="lora.txSignalBandwidth"]');
+const LoRaPower                     = document.querySelector('[name="lora.power"]');
+const LoRaCadActive                 = document.querySelector('[name="lora.cadActive"]');
+LoRaTxCheckbox.addEventListener("change", function () {
+    LoRaTxFreq.disabled             = !this.checked;
+    LoRaTxSpreadingFactor.disabled  = !this.checked;
+    LoRaTxCodingRate.disabled       = !this.checked;
+    LoRaTxSignalBandwidth.disabled  = !this.checked;
+    LoRaPower.disabled              = !this.checked;
+    LoRaCadActive.disabled          = !this.checked;
+});
+
 // Syslog Switches
 const SyslogCheckbox                = document.querySelector('input[name="syslog.active"]');
 const SyslogServer                  = document.querySelector('input[name="syslog.server"]');
@@ -559,7 +603,7 @@ function loadReceivedPackets(packets) {
 
         packets.forEach((packet) => {
             const element = document.createElement("tr");
-        
+
             element.innerHTML = `
                         <td>${packet.rxTime}</td>
                         <td>${packet.packet}</td>
@@ -592,7 +636,7 @@ document.querySelector('a[href="/received-packets"]').addEventListener('click',
 
     document.getElementById('received-packets').classList.remove('d-none');
     document.getElementById('configuration').classList.add('d-none');
-    
+
     document.querySelector('button[type=submit]').remove();
 
     fetchReceivedPackets();

include/configuration.h

@@ -86,6 +86,7 @@ public:
     int     txCodingRate4;
     long    txSignalBandwidth;
     int     power;
+    bool    cadActive;
 };
 
 class Display {

src/LoRa_APRS_iGate.cpp

@@ -68,8 +68,8 @@ ___________________________________________________________________*/
 #endif
 
 
-String              versionDate             = "2026-04-21";
-String              versionNumber           = "3.2.4";
+String              versionDate             = "2026-06-11";
+String              versionNumber           = "3.3.0";
 Configuration       Config;
 WiFiClient          aprsIsClient;
 WiFiClient          mqttClient;

src/aprs_is_utils.cpp

@@ -16,7 +16,7 @@
  * along with LoRa APRS iGate. If not, see <https://www.gnu.org/licenses/>.
  */
 
-#include <APRSPacketLib.h> 
+#include <APRSPacketLib.h>
 #include <WiFiClient.h>
 #include "configuration.h"
 #include "network_manager.h"
@@ -47,7 +47,6 @@ extern bool                 modemLoggedToAPRSIS;
 extern bool                 backupDigiMode;
 extern String               versionNumber;
 
-uint32_t    lastRxTime      = millis();
 bool        passcodeValid   = false;
 uint32_t    lastServerCheck = 0;
 
@@ -403,7 +402,6 @@ namespace APRS_IS_Utils {
                     String aprsisPacket = aprsIsClient.readStringUntil('\r');
                     aprsisPacket.trim();    // Serial.println(aprsisPacket);
                     processAPRSISPacket(aprsisPacket);
-                    lastRxTime = millis();
                 }
             }
         #endif

src/configuration.cpp

@@ -106,6 +106,7 @@ bool Configuration::writeFile() {
         data["lora"]["txCodingRate4"]               = loramodule.txCodingRate4;
         data["lora"]["txSignalBandwidth"]           = loramodule.txSignalBandwidth;
         data["lora"]["power"]                       = loramodule.power;
+        data["lora"]["cadActive"]                   = loramodule.cadActive;
 
         int rxSpreadingFactor = loramodule.rxSpreadingFactor;
         int txSpreadingFactor = loramodule.txSpreadingFactor;
@@ -290,7 +291,6 @@ bool Configuration::readFile() {
         #endif
         digi.backupDigiMode             = data["digi"]["backupDigiMode"] | false;
 
-
         if (data["lora"]["rxActive"].isNull() ||
             data["lora"]["rxFreq"].isNull() ||
             data["lora"]["rxSpreadingFactor"].isNull() ||
@@ -301,7 +301,8 @@ bool Configuration::readFile() {
             data["lora"]["txSpreadingFactor"].isNull() ||
             data["lora"]["txCodingRate4"].isNull() ||
             data["lora"]["txSignalBandwidth"].isNull() ||
-            data["lora"]["power"].isNull()) needsRewrite = true;
+            data["lora"]["power"].isNull() ||
+            data["lora"]["cadActive"].isNull()) needsRewrite = true;
         loramodule.rxActive             = data["lora"]["rxActive"] | true;
         loramodule.rxFreq               = data["lora"]["rxFreq"] | 433775000;
         loramodule.rxSpreadingFactor    = data["lora"]["rxSpreadingFactor"] | 12;
@@ -313,6 +314,7 @@ bool Configuration::readFile() {
         loramodule.txCodingRate4        = data["lora"]["txCodingRate4"] | 5;
         loramodule.txSignalBandwidth    = data["lora"]["txSignalBandwidth"] | 125000;
         loramodule.power                = data["lora"]["power"] | 20;
+        loramodule.cadActive            = data["lora"]["cadActive"] | true;
 
         if (data["display"]["alwaysOn"].isNull() ||
             data["display"]["timeout"].isNull() ||
@@ -503,6 +505,7 @@ void Configuration::setDefaultValues() {
     loramodule.txCodingRate4        = 5;
     loramodule.txSignalBandwidth    = 125000;
     loramodule.power                = 20;
+    loramodule.cadActive            = true;
 
     display.alwaysOn                = true;
     display.timeout                 = 4;

src/lora_utils.cpp

@@ -28,15 +28,19 @@
 #include "utils.h"
 
 
+
+
 extern Configuration    Config;
 extern NetworkManager   *networkManager;
-extern uint32_t         lastRxTime;
 extern bool             packetIsBeacon;
 
 extern std::vector<ReceivedPacket> receivedPackets;
 
-bool operationDone   = true;
-bool transmitFlag    = true;
+bool operationDone      = true;
+bool transmitFlag       = true;
+
+#define DIFS_SLOTS      2       // Number of secuential CAD slots to consider a free channel to Tx
+int  backoffMax         = 4;    // Max Backoff value (number of CAD slots to wait before Tx)
 
 #ifdef HAS_SX1262
     SX1262 radio = new Module(RADIO_CS_PIN, RADIO_DIO1_PIN, RADIO_RST_PIN, RADIO_BUSY_PIN);
@@ -167,6 +171,34 @@ namespace LoRa_Utils {
         radio.setBandwidth(signalBandwidth);
     }
 
+    bool doCAD() {      // CAD (Channel Activity Detection)
+        return radio.scanChannel() != RADIOLIB_CHANNEL_FREE;    // false=channel free | true=RADIOLIB_LORA_DETECTED or CAD failed
+    }
+
+    bool doDIFS() {
+        for (uint8_t i = DIFS_SLOTS; i > 0; i--) {
+            if (doCAD()) return false;
+        }
+        return true;
+    }
+
+    void waitForDIFS() {
+        while (!doDIFS()) {
+            Serial.println("CAD/DIFS failed, retry...");
+        }
+    }
+
+    void doBEB() {
+        int backoffCounter = random(1, backoffMax + 1);
+        while (backoffCounter > 0) {
+            if (doCAD()) {
+                waitForDIFS();  // busy channel: freeze backoff and restart DIFS
+            } else {
+                backoffCounter--;
+            }
+        }
+    }
+
     void sendNewPacket(const String& newPacket) {
         if (!Config.loramodule.txActive) return;
 
@@ -179,6 +211,12 @@ namespace LoRa_Utils {
         #ifdef INTERNAL_LED_PIN
             if (Config.digi.ecoMode != 1) digitalWrite(INTERNAL_LED_PIN, HIGH);     // disabled in Ultra Eco Mode
         #endif
+
+        if (Config.loramodule.cadActive) {
+            waitForDIFS();  // DIFS (Distributed Inter-Frame Space)
+            doBEB();        // BEB  (Binary Exponential Backoff)
+        }
+
         int state = radio.transmit("\x3c\xff\x01" + newPacket);
         transmitFlag = true;
         if (state == RADIOLIB_ERR_NONE) {
@@ -250,7 +288,6 @@ namespace LoRa_Utils {
                         } else {
                             packet = "";
                         }
-                        lastRxTime = millis();
                         return packet;
                     }
                 } else if (state == RADIOLIB_ERR_CRC_MISMATCH) {

src/station_utils.cpp

@@ -25,15 +25,11 @@
 #include "utils.h"
 #include <vector>
 
-#define SECS_TO_WAIT            3   // soon to be deleted...
-
 
 extern Configuration            Config;
-extern uint32_t                 lastRxTime;
 extern String                   fourthLine;
 extern bool                     shouldSleepLowVoltage;
 
-uint32_t lastTxTime             = millis();
 std::vector<LastHeardStation>   lastHeardStations;
 std::vector<String>             blacklist;
 std::vector<String>             managers;
@@ -214,15 +210,11 @@ namespace STATION_Utils {
     }
 
     void processOutputPacketBuffer() {
-        int timeToWait                  = SECS_TO_WAIT * 1000;          // 3 segs between packet Tx and also Rx ???
-        uint32_t lastRx                 = millis() - lastRxTime;
-        uint32_t lastTx                 = millis() - lastTxTime;
-        if (outputPacketBuffer.size() > 0 && lastTx > timeToWait && lastRx > timeToWait) {
+        if (outputPacketBuffer.size() > 0) {
             if (outputPacketBuffer[0].isBeacon) packetIsBeacon = true;
             LoRa_Utils::sendNewPacket(outputPacketBuffer[0].packet);
             if (outputPacketBuffer[0].isBeacon) packetIsBeacon = false;
             outputPacketBuffer.erase(outputPacketBuffer.begin());
-            lastTxTime = millis();
         }
         if (shouldSleepLowVoltage) {
             while (outputPacketBuffer.size() > 0) {

src/web_utils.cpp

@@ -213,6 +213,8 @@ namespace WEB_Utils {
         Config.loramodule.txCodingRate4     = getParamIntSafe("lora.txCodingRate4", Config.loramodule.txCodingRate4);
         Config.loramodule.txSignalBandwidth = getParamIntSafe("lora.txSignalBandwidth", Config.loramodule.txSignalBandwidth);
         Config.loramodule.power             = getParamIntSafe("lora.power", Config.loramodule.power);
+        if (Config.loramodule.txActive)
+            Config.loramodule.cadActive     = request->hasParam("lora.cadActive", true);
 
         Config.display.alwaysOn             = request->hasParam("display.alwaysOn", true);
         if (!Config.display.alwaysOn) {