#include <SPI.h>
//#include <nRF24L01.h>
#include <RF24.h>
#include <Button.h>

#define RADIO_CE_PIN 7
#define RADIO_CS_PIN 6

RF24 radio(RADIO_CE_PIN, RADIO_CS_PIN); // CE, CSN pins

const byte address[6] = "00001";
const int txButtonPin = 2; // Pin connected to the button
const int txLedPin = 12;

const char text[13] = "Hello, world!";

byte lastAckTimeMs = 0;
bool lastSendResult = true;

Button txButton(txButtonPin); // Connect your button between pin 2 and GND

void setup() {
  Serial.begin(9600);
  pinMode(txLedPin, OUTPUT); // Initialize LED pin as output
  //radio.begin();
  radio.openWritingPipe(address);
  radio.setPALevel(RF24_PA_HIGH);
  radio.setRetries(15, 15);
  //------- added 17/08/2025
  radio.setChannel(115);
  radio.setAutoAck(true);
  radio.setPayloadSize(sizeof(text));
  radio.openReadingPipe(1, address);
  radio.begin();
  // ------------------

  txButton.begin();
}

void loop() {
  toggleTxButton();
}

void toggleTxButton() {
  // Toggled txButton
  if (txButton.toggled()) {
    if (txButton.read() == Button::PRESSED) {
      Serial.println("txButton has been pressed: activate transmission");
      digitalWrite(txLedPin, HIGH);
      
      // Stop listening, send data, then start listening again
      radio.stopListening(); // Prepare for transmission
      radio.printPrettyDetails();
      randomSeed(analogRead(0));
      sendData();
      delay(500); // Debounce delay
      
      radio.startListening(); // Switch back to receiving mode
    } else {
      Serial.println("txButton has been released: stop transmission");
      digitalWrite(txLedPin, LOW);
      
      // Check for incoming data
      receiveData();
    }
  }
}

void sendData() {

  // if (!radio.begin()) {
  //   Serial.println(F("Radio hardware is not responding!"));
  //   while (1) {} // hold in infinite loop
  // }

  Serial.print("Sending: ");
  Serial.println(text);  // Print the data being sent
  
  unsigned long startTime = millis();
  lastSendResult = radio.write(&text, sizeof(text));
  unsigned long currentTime = millis();
  lastAckTimeMs = currentTime - startTime;

  // Serial.print("Tx Start Time: ");
  // Serial.print(startTime);
  // Serial.print(", Tx Current Time: ");
  // Serial.print(currentTime);
  // Serial.print(", Last Ack Time MS: ");
  // Serial.println(lastAckTimeMs);

  if (lastSendResult) {
    Serial.println("Data sent.");
  } else {
    Serial.println("Data send failed.");
  }
  
  delay(1000); // Small delay to ensure stability
}


void receiveData() {

  // if (!radio.begin()) {
  //   Serial.println(F("Radio hardware is not responding!"));
  //   while (1) {} // hold in infinite loop
  // }
  
  radio.startListening(); // Ensure the radio is in listening mode
   
  if (radio.available()) {

    char text[32] = "";
    radio.read(&text, sizeof(text));
    
    // Print the received data
    Serial.print("Received: '");
    Serial.print(text);
    Serial.println("'");
    
    // Debugging: Print each character in hexadecimal
    for (int i = 0; i < sizeof(text); i++) {
      Serial.print(text[i], HEX);
      Serial.print(" ");
    }
    Serial.println();
  } else {
    Serial.println("No data received.");
  }
}