TODO: Implement real gps data - Bugfix - working now

LoRaReceiver/LoRaReceiver.ino

@@ -1,5 +1,8 @@
 #include <SPI.h>
 #include <LoRa.h>
+#include <Wire.h>
+#include <Adafruit_GFX.h>
+#include <Adafruit_SSD1306.h>
 
 #define SYNC_WORD 0xCE
 #define SENDER_ID 0xAA
@@ -13,23 +16,29 @@
 #define LORA_IRQ 26
 #define LORA_FREQ 868E6
 
+// OLED Settings
+#define SCREEN_WIDTH 128
+#define SCREEN_HEIGHT 64
+#define OLED_RESET -1
+Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
+
 void sendMessage(const String& msg) {
   LoRa.beginPacket();
   LoRa.write(SYNC_WORD);
-  LoRa.write(SELF_ID);
+  LoRa.write(SENDER_ID);
   LoRa.write(msg.length());
   LoRa.print(msg);
   LoRa.endPacket(true);
 }
 
 bool receiveMessage(String& out) {
-  int packetSize = LoRa.parsePacket();
-  if (!packetSize) return false;
+  LoRa.parsePacket();
 
   byte sync = LoRa.read();
   byte sender = LoRa.read();
-  if (sync != SYNC_WORD || sender != SENDER_ID) {
+  if (sync != SYNC_WORD || sender != SELF_ID) {
     LoRa.flush();
+    // Serial.println("Unidentifiziertes Paket: " + String(sync) + String(sender));
     return false;
   }
 
@@ -39,63 +48,87 @@ bool receiveMessage(String& out) {
 
   if (data.length() != len) {
     out = "ERR: LEN";
-    return true;
+  } else {
+    out = data;
+    sendMessage("ACK");
   }
-
-  sendMessage("ACK");
-  out = data;
   return true;
 }
 
+void showOnOLED(const String& line1, const String& line2 = "", const String& line3 = "") {
+  display.clearDisplay();
+  display.setTextSize(1);
+  display.setTextColor(SSD1306_WHITE);
+  display.setCursor(0, 0);
+  display.println(line1);
+  if (line2.length()) {
+    display.setCursor(0, 16);
+    display.println(line2);
+  }
+  if (line3.length()) {
+    display.setCursor(0, 32);
+    display.println(line3);
+  }
+  display.display();
+}
+
 void printHelp() {
   Serial.println("g – Standort anfragen\nh – Hilfe");
+  showOnOLED("Befehle:", "g Standort / h Hilfe");
 }
 
-void handleCommandG(){
+void handleCommandG() {
   sendMessage("g");
   unsigned long t0 = millis();
   String answer;
   while (millis() - t0 < 1000) {
     if (receiveMessage(answer)) {
       Serial.println(answer);
-      break;
+      showOnOLED("Antwort von Sender:", answer);
+      return;
     }
     delay(10);
   }
-  if (millis() - t0 >= 1000) Serial.println("Timeout");
+  Serial.println("Timeout");
+  showOnOLED("Timeout beim", "Empfangen");
 }
 
 void setup() {
   Serial.begin(115200);
+
+  // OLED init
+  Wire.begin();  // SDA/SCL Default
+  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
+    Serial.println("OLED init fehlgeschlagen");
+    while (1) delay(1000);
+  }
+  showOnOLED("LoRa OLED Init", "Bitte warten...");
+
+  // LoRa init
   SPI.begin(LORA_SCK, LORA_MISO, LORA_MOSI, LORA_CS);
   LoRa.setPins(LORA_CS, LORA_RST, LORA_IRQ);
   if (!LoRa.begin(LORA_FREQ)) {
-    while (true) {
-      Serial.println("Konnte LoRa nicht initialisieren!\nBitte neustarten!");
-      delay(1000);
-    }
+    Serial.println("Konnte LoRa nicht initialisieren!");
+    showOnOLED("LoRa Init fehl", "Neustart nötig");
+    while (1) delay(1000);
   }
   LoRa.enableCrc();
-  // LoRa.setSyncWord(SYNC_WORD); // this would have been simpler nevermind
+  showOnOLED("LoRa bereit", "Creator:", "Timo Niemann");
 }
 
 void loop() {
   if (Serial.available()) {
     char cmd = Serial.read();
     switch (cmd) {
-      case 'h':
-        printHelp();
-        break;
-      case 'g':
-        handleCommandG();
-        break;
-      default:
-        printHelp();
-        break;
+      case 'h': printHelp(); break;
+      case 'g': handleCommandG(); break;
+      default: printHelp(); break;
     }
   }
 
-  // passive listening
   String msg;
-  if (receiveMessage(msg)) Serial.printf("RX: %s\n", msg.c_str());
+  if (receiveMessage(msg)) {
+    Serial.printf("RX: %s\n", msg.c_str());
+    showOnOLED("Empfangen:", msg);
+  }
 }