In below code while sending data from second node to first node(sending data from first node to second node no issue) while there is " no ACK received" received by second node at the time of sening data first node print that data 3 times and also prints " ACK sent" . How do i solve this issue?
// RFM69HCW Example Sketch
// Send serial input characters from one RFM69 node to another
// Based on RFM69 library sample code by Felix Rusu
// http://LowPowerLab.com/contact
// Modified for RFM69HCW by Mike Grusin, 4/16
// This sketch will show you the basics of using an
// RFM69HCW radio module. SparkFun's part numbers are:
// 915MHz: https://www.sparkfun.com/products/12775
// 434MHz: https://www.sparkfun.com/products/12823
// See the hook-up guide for wiring instructions:
// https://learn.sparkfun.com/tutorials/rfm69hcw-hookup-guide
// Uses the RFM69 library by Felix Rusu, LowPowerLab.com
// Original library: https://www.github.com/lowpowerlab/rfm69
// SparkFun repository: https://github.com/sparkfun/RFM69HCW_Breakout
// Include the RFM69 and SPI libraries:
#include <RFM69.h>
#include <SPI.h>
// Addresses for this node. CHANGE THESE FOR EACH NODE!
#define NETWORKID 0 // Must be the same for all nodes
#define MYNODEID 1 // My node ID
#define TONODEID 2 // Destination node ID
// RFM69 frequency, uncomment the frequency of your module:
//#define FREQUENCY RF69_433MHZ
#define FREQUENCY RF69_915MHZ
// AES encryption (or not):
#define ENCRYPT true // Set to "true" to use encryption
#define ENCRYPTKEY "TOPSECRETPASSWRD" // Use the same 16-byte key on all nodes
// Use ACKnowledge when sending messages (or not):
#define USEACK true // Request ACKs or not
// Packet sent/received indicator LED (optional):
#define LED 9 // LED positive pin
#define GND 8 // LED ground pin
// Create a library object for our RFM69HCW module:
RFM69 radio;
void setup()
{
// Open a serial port so we can send keystrokes to the module:
Serial.begin(9600);
Serial.print("Node ");
Serial.print(MYNODEID,DEC);
Serial.println(" ready");
// Set up the indicator LED (optional):
pinMode(LED,OUTPUT);
digitalWrite(LED,LOW);
pinMode(GND,OUTPUT);
digitalWrite(GND,LOW);
// Initialize the RFM69HCW:
// radio.setCS(10); //uncomment this if using Pro Micro
radio.initialize(FREQUENCY, MYNODEID, NETWORKID);
radio.setHighPower(); // Always use this for RFM69HCW
// Turn on encryption if desired:
if (ENCRYPT)
radio.encrypt(ENCRYPTKEY);
}
void loop()
{
// Set up a "buffer" for characters that we'll send:
static char sendbuffer[62];
static int sendlength = 0;
// SENDING
// In this section, we'll gather serial characters and
// send them to the other node if we (1) get a carriage return,
// or (2) the buffer is full (61 characters).
// If there is any serial input, add it to the buffer:
if (Serial.available() > 0)
{
char input = Serial.read();
if (input != '\r') // not a carriage return
{
sendbuffer[sendlength] = input;
sendlength++;
}
// If the input is a carriage return, or the buffer is full:
if ((input == '\r') || (sendlength == 61)) // CR or buffer full
{
// Send the packet!
Serial.print("sending to node ");
Serial.print(TONODEID, DEC);
Serial.print(", message [");
for (byte i = 0; i < sendlength; i++)
Serial.print(sendbuffer[i]);
Serial.println("]");
// There are two ways to send packets. If you want
// acknowledgements, use sendWithRetry():
if (USEACK)
{
if (radio.sendWithRetry(TONODEID, sendbuffer, sendlength))
Serial.println("ACK received!");
else
Serial.println("no ACK received");
}
// If you don't need acknowledgements, just use send():
else // don't use ACK
{
radio.send(TONODEID, sendbuffer, sendlength);
}
sendlength = 0; // reset the packet
Blink(LED,10);
}
}
// RECEIVING
// In this section, we'll check with the RFM69HCW to see
// if it has received any packets:
if (radio.receiveDone()) // Got one!
{
// Print out the information:
Serial.print("received from node ");
Serial.print(radio.SENDERID, DEC);
Serial.print(", message [");
// The actual message is contained in the DATA array,
// and is DATALEN bytes in size:
for (byte i = 0; i < radio.DATALEN; i++)
Serial.print((char)radio.DATA[i]);
// RSSI is the "Receive Signal Strength Indicator",
// smaller numbers mean higher power.
Serial.print("], RSSI ");
Serial.println(radio.RSSI);
// Send an ACK if requested.
// (You don't need this code if you're not using ACKs.)
if (radio.ACKRequested())
{
radio.sendACK();
Serial.println("ACK sent");
}
Blink(LED,10);
}
}
void Blink(byte PIN, int DELAY_MS)
// Blink an LED for a given number of ms
{
digitalWrite(PIN,HIGH);
delay(DELAY_MS);
digitalWrite(PIN,LOW);
}