#include <esp_now.h>
#include <WiFi.h>


#define POT_PIN D0 // Potentiometer connected to pin D0

// Define the structure for sending data
typedef struct struct_message {
  int value;
} struct_message;

struct_message myData;

// Define the peer address (MAC address of the receiver)
uint8_t broadcastAddress[] = {0xD4, 0xF9, 0x8D, 0x00, 0xF9, 0x18}; // Replace with the receiver's MAC address

// Callback function that gets called when data is sent
void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
  Serial.print("Last Packet Send Status: ");
  Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
}

// Global variables
int bpm = 60; // Default BPM
unsigned long lastToggleTime = 0;
unsigned long lastReadTime = 0;
const unsigned long readInterval = 500; // Delay for reading the potentiometer (in milliseconds)

void setup() {
  // Initialize Serial Monitor
  Serial.begin(115200);

  // Set device as a Wi-Fi Station
  WiFi.mode(WIFI_STA);
  Serial.println("WiFi mode set to STA");

  // Init ESP-NOW
  if (esp_now_init() != ESP_OK) {
    Serial.println("Error initializing ESP-NOW");
    return;
  }
  Serial.println("ESP-NOW initialized");

  // Register the send callback
  esp_now_register_send_cb(OnDataSent);

  // Register peer
  esp_now_peer_info_t peerInfo;
  memcpy(peerInfo.peer_addr, broadcastAddress, 6);
  peerInfo.channel = 0;  
  peerInfo.encrypt = false;

  // Add peer        
  if (esp_now_add_peer(&peerInfo) != ESP_OK) {
    Serial.println("Failed to add peer");
    return;
  }
  Serial.println("Peer added");

}

void loop() {
  // Get the current time
  unsigned long currentTime = millis();

  // Check if it's time to read the potentiometer and send data
  if (currentTime - lastReadTime >= readInterval) {
    // Read the analog value from the potentiometer
    int analogValue = analogRead(POT_PIN); // Pin D1 corresponds to ADC1 (GPIO1)
    
    // Map the analog value to the range 30 to 180
    bpm = map(analogValue, 0, 4095, 30, 180); // Assuming a 12-bit ADC resolution
    
    // Print the values for debugging
    Serial.print("Analog Value: ");
    Serial.print(analogValue);
    Serial.print(" | Mapped Value: ");
    Serial.println(bpm);

    // Prepare data to send
    myData.value = bpm;

    // Send message via ESP-NOW
    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");
    }

    // Update the last read time
    lastReadTime = currentTime;
  }

}