/************************************************************************************************* 
                                      PROGRAMMINFO
************************************************************************************************** 
Funktion: ESP32 Sender Code (ESP-NOW)
**************************************************************************************************
Version: 18.09.2021
*************************************************************************************************
Board: ESP36 Dev Module
**************************************************************************************************
C++ Arduino IDE V1.8.13
**************************************************************************************************
Einstellungen:
https://dl.espressif.com/dl/package_esp32_index.json
http://dan.drown.org/stm32duino/package_STM32duino_index.json
https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_dev_index.json
**************************************************************************************************
Librarys
- WiFi.h V0.16.1
 **************************************************************************************************/

#include <esp_now.h>
#include <esp_wifi.h>
#include <WiFi.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>

// Board ID festlegen:
#define BOARD_ID 1

// DHT Sensor PIN
#define DHTPIN 4  

// Sensortype auswählen:
//#define DHTTYPE    DHT11     // DHT 11
#define DHTTYPE    DHT22     // DHT 22 (AM2302)
//#define DHTTYPE    DHT21     // DHT 21 (AM2301)

DHT dht(DHTPIN, DHTTYPE);

//Receiver MAC Addresse 
uint8_t broadcastAddress[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};

typedef struct struct_message {
    int id;
    float temp;
    float hum;
    int readingId;
} struct_message;

struct_message myData;

unsigned long previousMillis = 0;   
const long interval = 10000;        // Sensor Intervall

unsigned int readingId = 0;

constexpr char WIFI_SSID[] = "R2-D2";

int32_t getWiFiChannel(const char *ssid) {
  if (int32_t n = WiFi.scanNetworks()) {
      for (uint8_t i=0; i<n; i++) {
          if (!strcmp(ssid, WiFi.SSID(i).c_str())) {
              return WiFi.channel(i);
          }
      }
  }
  return 0;
}

float readDHTTemperature() {
  float t = dht.readTemperature();
  if (isnan(t)) {    
    Serial.println("T DHT Sensor Fehler!");
    return 0;
  }
  else {
    Serial.println(t);
    return t;
  }
}

float readDHTHumidity() {
  float h = dht.readHumidity();
  if (isnan(h)) {
    Serial.println("F DHT Sensor Fehler!");
    return 0;
  }
  else {
    Serial.println(h);
    return h;
  }
}


void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
  Serial.print("\r\nLast Packet Send Status:\t");
  Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
}
 
void setup() {
  Serial.begin(115200);

  dht.begin();
 
  WiFi.mode(WIFI_STA);

  int32_t channel = getWiFiChannel(WIFI_SSID);

  WiFi.printDiag(Serial); 
  esp_wifi_set_promiscuous(true);
  esp_wifi_set_channel(channel, WIFI_SECOND_CHAN_NONE);
  esp_wifi_set_promiscuous(false);
  WiFi.printDiag(Serial); 

  //Init ESP-NOW
  if (esp_now_init() != ESP_OK) {
    Serial.println("Error initializing ESP-NOW");
    return;
  }
  esp_now_register_send_cb(OnDataSent);
  
  esp_now_peer_info_t peerInfo;
  memcpy(peerInfo.peer_addr, broadcastAddress, 6);
  peerInfo.encrypt = false;
        
  if (esp_now_add_peer(&peerInfo) != ESP_OK){
    Serial.println("Failed to add peer");
    return;
  }
}
 
void loop() {
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval) {

    previousMillis = currentMillis;

    myData.id = BOARD_ID;
    myData.temp = readDHTTemperature();
    myData.hum = readDHTHumidity();
    myData.readingId = readingId++;
     
    esp_err_t result = esp_now_send(broadcastAddress, (uint8_t *) &myData, sizeof(myData));
    if (result == ESP_OK) {
      Serial.println("Sent with success");
    }
    else {
      Serial.println("Error sending the data");
    }
  }
}