Send and receive Accelerometer Data from ADXL 335 through NRF24l01

Using Arduino Project Guidance
3

The first and most difficult part is going to be getting the rf24 radios to communicate. Have you done that yet? If not, I suggest that you read and carefully follow Robin2's simple rf24 tutorial. That helped me a lot.

Here are examples that you may modify to do what you want. The sender will acquire 4 analog values from joysticks, put the values into a struct payload and transmit them. The other will receive the struct payload and separate those values.

Sender

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

const byte CE_PIN = 9;
const byte CSN_PIN = 10;

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

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

struct JoyValues
{
  int joy1x;
  int joy1y;
  int joy2x;
  int joy2y;
}joyValues;

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

const byte joy1xPin = A0;
const byte joy1yPin = A1;
const byte joy2xPin = A2;
const byte joy2yPin = A3;

void setup()
{
   Serial.begin(115200);
   Serial.println("SimpleTx Starting");
      
   radio.begin();
   radio.setChannel(76);  //76 library default
   //RF24_PA_MIN, RF24_PA_LOW, RF24_PA_HIGH and RF24_PA_MAX
   radio.setPALevel(RF24_PA_HIGH);
   radio.setDataRate( RF24_250KBPS );
   radio.setRetries(3, 5); // delay, count
   radio.openWritingPipe(slaveAddress);
}

void loop()
{
   currentMillis = millis();
   if (currentMillis - prevMillis >= txIntervalMillis)
   {
      send();
      Serial.print("JOY 1 X = ");
      Serial.print( joyValues.joy1x);
      Serial.print("  JOY 1 Y = ");
      Serial.print( joyValues.joy1y);
      Serial.print("  JOY 2 X = ");
      Serial.print( joyValues.joy2x);
      Serial.print("  JOY 2 Y = ");
      Serial.println( joyValues.joy2y);
      prevMillis = millis();
   }
}

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

void send()
{
   joyValues.joy1x = analogRead(joy1xPin);
   joyValues.joy1y = analogRead(joy1yPin);
   joyValues.joy2x = analogRead(joy2xPin);
   joyValues.joy2y = analogRead(joy2yPin);
   radio.write( &joyValues, sizeof(joyValues) );
}

Receiver:

// SimpleRx - the slave or the receiver

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

const byte CE_PIN = 9;
const byte CSN_PIN = 10;

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

RF24 radio(CE_PIN, CSN_PIN);

struct JoyValues
{
  int joy1x;
  int joy1y;
  int joy2x;
  int joy2y;
}joyValues;

bool newData = false;

//===========
void setup()
{
   Serial.begin(115200);
   Serial.println("SimpleRx Starting");

   radio.begin();
   radio.setChannel(76);  //76 library default
   //RF24_PA_MIN, RF24_PA_LOW, RF24_PA_HIGH and RF24_PA_MAX
   radio.setPALevel(RF24_PA_HIGH);
   radio.setDataRate( RF24_250KBPS );
   radio.openReadingPipe(1, thisSlaveAddress);
   radio.startListening();
}

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

void loop()
{
   getData();
   showData();
}

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

void getData()
{
   if ( radio.available() )
   {
      radio.read( &joyValues, sizeof(joyValues) );
      newData = true;
   }
}

void showData()
{
   if (newData == true)
   {
      Serial.print("Data received >> ");
       Serial.print("JOY 1 X = ");
      Serial.print( joyValues.joy1x);
      Serial.print("  JOY 1 Y = ");
      Serial.print( joyValues.joy1y);
      Serial.print("  JOY 2 X = ");
      Serial.print( joyValues.joy2x);
      Serial.print("  JOY 2 Y = ");
      Serial.println( joyValues.joy2y);
      newData = false;
   }
}
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