Added code tested with radio modules.

src/main.cpp

@@ -23,97 +23,144 @@ TinyGPSPlus gps;                     // TinyGPS++ object to process GPS data
 RH_RF95 rf95(RFM9X_CS, RMF9X_INT);  // Radio instance.
 
 
-typedef struct Msg{
-    uint8_t id;
-    double latitude;
-    double longitude;
-    uint8_t crc;
-}Msg;
-
-
 // Variables
 static int prevHeading = -1;         // Store previous heading to avoid frequent updates
 unsigned long lastUpdate = 0;        // Time tracking for updates
 const int updateInterval = 500;      // Update interval in milliseconds (500ms = 0.5s)
-NodeId node = {
-    id = 0;
-    name = "name";
+
+typedef struct MSG{
+  uint8_t id;
+  double latitude;
+  double longitude;
+}MSG;
+
+
+enum result {
+  Ok = 0,
+  Err,
+  ReceiveFailed,
+  NoReply,
 };
-uint8_t reciver_buffer[RF9X_BUF_SZ];
 
-void Radio_setup(void) {
-    pinMode(RFM9X_RST, OUTPUT);
-    digitalWrite(RFM9X_RST, HIGH);
+uint8_t db; //Used to hold the current setting for the TX power.
+uint8_t buffer[sizeof(MSG)];
 
-    while(!rf95.init()){}
-    Serial.println("radio: Initialized");
+MSG msg_out;
+msg_out.id = 0;   //Put the system ID here
 
-    if(rf95.setFrequency(RF9X_FREQ)) {
-        Serial.println("radio: Error could not set frequency");
-        while(true){} //Loop forever
-    }
-    Serial.print("radio: Frequency = ");
-    Serial.println(RF9X_FREQ);
 
-    rf95.setTxPower(RF9X_MIN_DB, false);
+void MSG_Print(MSG *msg) {
+  Serial.print("ID: ");
+  Serial.println(msg->id);
+
+  Serial.print("Latitude: ");
+  Serial.println(msg->latitude);
+
+  Serial.print("Longitude: ");
+  Serial.println(msg->longitude);
 }
 
-
-void Radio_reset(void) {
+void Radio_Reset(void) {
   digitalWrite(RFM9X_RST, LOW);
   delay(10);
   digitalWrite(RFM9X_RST, HIGH);
   delay(10);
 }
 
+uint8_t Radio_Setup(void) {
+  Serial.println("Radio_Setup()");
 
-int Radio_SendData() {
-    int8_t tx_power = RF9X_MIN_DB;   
-    uint8_t received_id = 0;
+  pinMode(RFM95_RST, OUTPUT);
+  digitalWrite(RFM95_RST, HIGH);
 
-    //Set the radio output to lowest power.
-    rf95.setTxPower(tx_power, false);
-
-    //Set the radio into TX mode.
-    rf95.setModeTx();
-
-    //Try transmitting data
-    Serial.println("Radio: Sending data...");
-    rf95.send(node.id, 1);
-    rf95.waitPacketSent();
-
-    //Wait for ACK or Radio Msg. (Timeout Should be included).
-    //On timeout increase the transmit power and re-attempt.
-    if(!rf95.waitAvailbleTimeout(RF9X_TIMEOUT)) {
-        if(rf95.recv(reciver_buffer, RF9X_BUF_SZ)) {
+  Radio_Reset();
 
+  while (!rf95.init()) {
+    Serial.println("Radio_Setup(): Failed to initialize");
+    Serial.println("Check SPI connections!");
+    return Err;
   }
-        else {
-            //Failed to receive the message.
-            Serial.println("Radio: Error failed to receive msg.");
-        }
-    }
-    else {
-        //No reply of any kind.
-        Serial.println("Radio: Error no reply.");
-    }
-
-    //Set the radio mode to idle.
-    rf95.setModeIdle();
+  Serial.println("LoRa radio init OK!");
+  return Ok;
 }
 
+uint8_t Radio_Configure(void) {
+  // Defaults after init are 434.0MHz, modulation GFSK_Rb250Fd250, +13dbM
+  if(!rf95.setFrequency(RF95_FREQ)) {
+    Serial.println("Radio_Configure(): failed to set frequency");
+    return Err;
+  }
+  Serial.print("Set Freq to: "); Serial.println(RF95_FREQ);
 
+  rf95.setTxPower(TX_POWER_LOW, false);
 
-int Radio_ReceiveData() {
-    //Set radio into RX mode.
-    rf95.setModeRx();
+  return Ok;
+}
 
-    //Check if radio has traffic
-    if()
+uint8_t Radio_SendMsg(MSG *msg) {
+  Serial.println("Radio_SendMsg()");
 
+  Serial.println("Sending Message: ");
+  Serial.print("Message size: ");
+  Serial.println(sizeof(MSG));
+
+  MSG_Print(msg);
+
+  rf95.send((uint8_t *)msg, sizeof(MSG));
+
+  Serial.println("waiting for packet sent...");
+  delay(10);
+  rf95.waitPacketSent();
+
+  return Ok;
+}
+
+uint8_t Radio_CheckForMsg(MSG *msg) {
+  Serial.println("Radio_CheckForMsg()");
+
+  //Now we wait for an packet.
+  if (rf95.waitAvailableTimeout(1000)) {
+    // Should be a reply message for us now
+    if (rf95.recv(buffer, sizeof(MSG))) {
+      Serial.print("Received reply: ");
+
+      msg->id = (uint8_t) buffer[0];
+      msg->latitude = *(double *) &buffer[1];
+      msg->longitude = *(double *) &buffer[5];
+
+      MSG_Print(msg);
+
+      Serial.print("RSSI: ");
+      Serial.println(rf95.lastRssi(), DEC);
+    } else {
+      Serial.println("Receive failed");
+      return ReceiveFailed;
+    }
+  } else {
+    Serial.println("No reply");
+    return NoReply;
+  }
+  return Ok;
+}
+
+//The algo below allows us to minimize the needed TX power.
+void Radio_Main(MSG *msg_out, MSG *msg_in) {
+  for(db = RF9X_MIN_DB; db <= RF9X_MAX_DB; db++) {
+    Radio_SendMsg(&msg_out);
+    if(Radio_CheckForMsg(&msg_in) == Ok) {
+      break;
+    }
+    else{
+      Serial.print("TX Power set to:");
+      Serial.println(db);
+    }
+  }
+
+  //We "delay" for 1 seconds by calling the radio check twice.
+  if(Radio_CheckForMsg(&msg_in) == Ok) {
+    Radio_SendMsg(&msg_out);
+  }
 
-    //Set the radio mode to idle.
-    rf95.setModeIdle();
 }
 
 
@@ -136,6 +183,24 @@ void setup(void) {
 
   // GPS Setup
   gpsSerial.begin(GPS_BUADRATE); 
+
+  // Setup the Radio module.
+
+  //Retry until sucsess.
+  for(uint8_t i = 0; i < RETRIES; i++) {
+    delay(100);
+    if(Radio_Setup() == Ok){
+      break;
+    }
+  }
+
+  //Retry configuration until success
+  for(uint8_t i = 0; i < RETRIES; i++) {
+    delay(100);
+    if(Radio_Configure() == Ok){
+      break;
+    }
+  }
 }
 
 void loop() {
@@ -145,12 +210,14 @@ void loop() {
   if (gpsSerial.available() > 0) {       // Check if data is available from the GPS module
     gps.encode(gpsSerial.read());        // Decode the GPS data
     if (gps.location.isValid()) {        // Check if GPS location data is valid
-      double latitude = gps.location.lat();  // Get latitude
-      double longitude = gps.location.lng(); // Get longitude
+      //double latitude = gps.location.lat();  // Get latitude
+      //double longitude = gps.location.lng(); // Get longitude
+      msg_out.latitude = gps.location.lat();
+      msg_out.longitude = gps.location.lat();
       Serial.print("Lat: ");                 // Output latitude for debugging
-      Serial.println(latitude, 6);           // Print latitude with 6 decimal places
+      Serial.println(msg_out.latitude, 6);           // Print latitude with 6 decimal places
       Serial.print("Lon: ");                 // Output longitude for debugging
-      Serial.println(longitude, 6);          // Print longitude with 6 decimal places
+      Serial.println(msg_out.longitude, 6);          // Print longitude with 6 decimal places
     } else {
       Serial.println("Waiting for valid GPS data...");  // GPS signal lost or invalid
     }
@@ -176,6 +243,9 @@ void loop() {
     updateDisplay();                  // Placeholder: Update the central TFT display with GPS data
     lastUpdate = currentTime;         // Reset the last update time
   }
+
+    //Handle the Radio data.
+
 }
 
 // Function to update the LED ring based on heading direction
@@ -220,6 +290,7 @@ void sendGPSData() {
   // - Format the data for transmission
   // - Use the LoRa library to send the data to the paired device
   // Example: LoRa.beginPacket(); LoRa.print(latitude); LoRa.print(longitude); LoRa.endPacket(); 
+
 }
 
 // Future function to receive GPS data from the other device via LoRa - See adafruit LORA code examples