// SimpleTx - the master or the transmitter

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


#define CE_PIN   20
#define CSN_PIN 17

const byte slaveAddress[5] = {'R','x','A','A','A'};


RF24 radio(CE_PIN, CSN_PIN); // Create a Radio

char command = '0';

unsigned long currentMillis;
unsigned long prevMillis;
unsigned long txIntervalMillis = 1000; // send once per second


void setup() {

    Serial.begin(9600);

    Serial.println("SimpleTx Starting");
    if (!radio.begin()) {
      while (true) {
        Serial.println("FUCK");
      }
    }
    radio.setPALevel(RF24_PA_HIGH);
    radio.setDataRate( RF24_250KBPS );
    radio.setRetries(3,5); // delay, count
    radio.enableAckPayload();
    // radio.setChannel(49);
    radio.openWritingPipe(slaveAddress);
    radio.stopListening();
}

//====================

void loop() {
    currentMillis = millis();
    if (currentMillis - prevMillis >= txIntervalMillis) {
        send();
        prevMillis = millis();
    }
}

//====================

void send() {
    bool rslt;
    if (Serial.available() > 0) {
      char command = Serial.read();  // Read a character from the Serial Monitor
    // Send the command wirelessly using your module
      rslt = radio.write( &command, sizeof(command) );
          // Always use sizeof() as it gives the size as the number of bytes.
          // For example if dataToSend was an int sizeof() would correctly return 2

      Serial.print("Data Sent ");
      Serial.print(command);
      if (rslt) {
          Serial.println("Acknowledge received");
      }
      else {
          Serial.println("Tx failed");
      }
    }
}