// SoftSerial-espnow-sender-receiver.ino
#include <ESP8266WiFi.h>
#include <espnow.h>
#include <SoftwareSerial.h>
 
#define MYPORT_TX 5  // D1  -> green    -> RXD der Gegenstelle
#define MYPORT_RX 4  // D2 <-  yellow  <-  TXD der Gegenstelle
SoftwareSerial myPort;


uint8_t receiverAddress[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};

const byte nachricht_length = 64;
typedef struct struct_message {
  char nachricht[nachricht_length];
} struct_message;

struct_message myData;
struct_message myData_in;

String nachricht[nachricht_length];
const boolean test_mode = true;
byte LED1 =  2;  // GPIO2  => D4 - onboard LED auf ESP8266 12E
byte LED2 = 16;  // GPIO16 => D0 - onboard LED auf NodeMCU Amica

void OnDataSent(uint8_t *mac_addr, uint8_t sendStatus) {
 if (sendStatus == 0) {
   if (test_mode) Serial.println("Delivery success");
 } else {
   if (test_mode) Serial.println("Delivery NOT success");
 }
}

void OnDataRecv(uint8_t * mac, uint8_t *incomingData, uint8_t len) {
  memcpy(&myData_in, incomingData, sizeof(myData_in));
  if (test_mode) {
    // Serial.println(String(len) + " - " + String(myData_in.nachricht));  
    Serial.println(String(myData_in.nachricht));  
  }
  myPort.println(String(myData_in.nachricht));
}

void setup() {
  Serial.begin(9600); delay(500); while ( Serial.available() ) Serial.read();
  Serial.println("\n\nSoftwareSerial-espnow-sender-receiver.ino\n");
  pinMode(LED1, OUTPUT);  digitalWrite(LED1, 1); //Aus
  pinMode(LED2, OUTPUT);  digitalWrite(LED2, 0); //AN  
  delay(1000);
  digitalWrite(LED1, 1); digitalWrite(LED2, 1);
  delay(1000);
  Serial.println("Initializing ESP-NOW ... ");
  WiFi.mode(WIFI_STA);
  while (esp_now_init() != 0) {
    if (test_mode) Serial.println(".");
    delay(1000); 
    digitalWrite(LED1, not digitalRead(LED1)); 
  }
  Serial.println("... ESP-NOW okay");

  esp_now_set_self_role(ESP_NOW_ROLE_COMBO);
  esp_now_register_send_cb(OnDataSent);

  esp_now_add_peer(receiverAddress, ESP_NOW_ROLE_SLAVE, 1, NULL, 0);
  esp_now_register_recv_cb(OnDataRecv);

  myPort.begin(9600, SWSERIAL_8N1, MYPORT_RX, MYPORT_TX, false);
  Serial.println("Teste SoftwareSerial ."); 
  while (!myPort) {
    digitalWrite(LED1, not digitalRead(LED1));
    Serial.print("."); 
    delay (500);
  } 
  Serial.println("\n OK");
  while (myPort.available()) {
    myPort.read();
  } 
}

byte result;

void loop() {
  if (test_mode && Serial.available()) {
    Serial.print("Eingabe: ");
    String eingabe = Serial.readStringUntil('\n');
    eingabe.trim();
    if (test_mode) Serial.println(eingabe);
    myPort.println(eingabe);
  }
  digitalWrite(LED2, not digitalRead(LED2));

  if (myPort.available()) { 
    String nachricht = "";
    char zeichen;
    while (myPort.available()) {
      zeichen = myPort.read();
      nachricht = nachricht + zeichen;
    }     //String nachricht = myPort.readStringUntil('\n');
    nachricht.trim();
    nachricht.toCharArray( myData.nachricht, nachricht_length );
    Serial.println("Sende " + nachricht);
    result = esp_now_send(receiverAddress, (uint8_t *) &myData, sizeof(myData));
    digitalWrite(LED1, not digitalRead(LED1)); 

  } else {

    //strcpy(myData.nachricht, "Nichts empfangen!");
    //Serial.println("Sende 'Nichts empfangen!'");
    digitalWrite(LED2, not digitalRead(LED2)); 
  }

  digitalWrite(LED2, not digitalRead(LED2));
  if (result != 0) {
    if (test_mode) Serial.println("\n Sending error");
    digitalWrite(LED1, not digitalRead(LED1));
  } else {
    if (test_mode) Serial.print(".");
  }
  delay(1000);
}