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

// Set the CE & CSN pins
#define CE_PIN   9
#define CSN_PIN 10
// Level Sensor Pin
#define PIN_TRIG 3
#define PIN_ECHO 2


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

// The tx/rx address
const byte rxAddr[6] = "00001";

void setup() {
  Serial.begin(115200);
  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);

   // Start the Radio!
  radio.begin();
  
  // Power setting. Due to likelihood of close proximity of the devices, set as RF24_PA_MIN (RF24_PA_MAX is default)
  radio.setPALevel(RF24_PA_MIN); // RF24_PA_MIN, RF24_PA_LOW, RF24_PA_HIGH, RF24_PA_MAX
  
  // Slower data rate for better range
  radio.setDataRate( RF24_250KBPS ); // RF24_250KBPS, RF24_1MBPS, RF24_2MBPS
  
  // Number of retries and set tx/rx address
  radio.setRetries(15, 15);
  radio.openWritingPipe(rxAddr);

  // Stop listening, so we can send!
  radio.stopListening();
}

void loop() {
  // Start a new measurement:
  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);

  // Read the result:
  int duration = pulseIn(PIN_ECHO, HIGH);
  Serial.print("Distance in CM: ");
  Serial.println(duration / 58);
  Serial.print("Distance in inches: ");
  Serial.println(duration / 148);
  int level=duration / 58;
  Serial.println(level);
  radio.write(level);

  delay(1000);
}