Transmit from Adafruit Feather 32u4 Radio to Arduino Uno

//
// RFM69HCW Example Sketch for Arduino pro mini
//
// 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);
}

//
// FEATHER
//
// rf69 demo tx rx.pde
// -*- mode: C++ -*-
// Example sketch showing how to create a simple messageing client
// with the RH_RF69 class. RH_RF69 class does not provide for addressing or
// reliability, so you should only use RH_RF69  if you do not need the higher
// level messaging abilities.
// It is designed to work with the other example rf69_server.
// Demonstrates the use of AES encryption, setting the frequency and modem
// configuration

#include <SPI.h>
#include <RH_RF69.h>

/************ Radio Setup ***************/

// Change to 434.0 or other frequency, must match RX's freq!
#define RF69_FREQ 915.0

#if defined (__AVR_ATmega32U4__) // Feather 32u4 w/Radio
  #define RFM69_CS      8
  #define RFM69_INT     7
  #define RFM69_RST     4
  #define LED           13
 
#elif defined(ADAFRUIT_FEATHER_M0) // Feather M0 w/Radio
  #define RFM69_CS      8
  #define RFM69_INT     3
  #define RFM69_RST     4
  #define LED           13
 
#elif defined (__AVR_ATmega328P__)  // Feather 328P w/wing
  #define RFM69_INT     3  //
  #define RFM69_CS      4  //
  #define RFM69_RST     2  // "A"
  #define LED           13

#elif defined(ESP8266)    // ESP8266 feather w/wing
  #define RFM69_CS      2    // "E"
  #define RFM69_IRQ     15   // "B"
  #define RFM69_RST     16   // "D"
  #define LED           0

#elif defined(ARDUINO_ADAFRUIT_FEATHER_ESP32S2)
  #define RFM69_INT     9  // "A"
  #define RFM69_CS      10  // "B"
  #define RFM69_RST     11  // "C"
  #define LED           13

#elif defined(ESP32)    // ESP32 feather w/wing
  #define RFM69_RST     13   // same as LED
  #define RFM69_CS      33   // "B"
  #define RFM69_INT     27   // "A"
  #define LED           13
#endif


/* Teensy 3.x w/wing
#define RFM69_RST     9   // "A"
#define RFM69_CS      10   // "B"
#define RFM69_IRQ     4    // "C"
#define RFM69_IRQN    digitalPinToInterrupt(RFM69_IRQ )
*/
 
/* WICED Feather w/wing
#define RFM69_RST     PA4     // "A"
#define RFM69_CS      PB4     // "B"
#define RFM69_IRQ     PA15    // "C"
#define RFM69_IRQN    RFM69_IRQ
*/

// Singleton instance of the radio driver
RH_RF69 rf69(RFM69_CS, RFM69_INT);

int16_t packetnum = 0;  // packet counter, we increment per xmission

void setup()
{
  Serial.begin(115200);
  //while (!Serial) { delay(1); } // wait until serial console is open, remove if not tethered to computer

  pinMode(LED, OUTPUT);    
  pinMode(RFM69_RST, OUTPUT);
  digitalWrite(RFM69_RST, LOW);

  Serial.println("Feather RFM69 TX Test!");
  Serial.println();

  // manual reset
  digitalWrite(RFM69_RST, HIGH);
  delay(10);
  digitalWrite(RFM69_RST, LOW);
  delay(10);
 
  if (!rf69.init()) {
    Serial.println("RFM69 radio init failed");
    while (1);
  }
  Serial.println("RFM69 radio init OK!");
  // Defaults after init are 434.0MHz, modulation GFSK_Rb250Fd250, +13dbM (for low power module)
  // No encryption
  if (!rf69.setFrequency(RF69_FREQ)) {
    Serial.println("setFrequency failed");
  }

  // If you are using a high power RF69 eg RFM69HW, you *must* set a Tx power with the
  // ishighpowermodule flag set like this:
  rf69.setTxPower(20, true);  // range from 14-20 for power, 2nd arg must be true for 69HCW

  // The encryption key has to be the same as the one in the server
  uint8_t key[] = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
                    0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08};
  rf69.setEncryptionKey(key);
 
  pinMode(LED, OUTPUT);

  Serial.print("RFM69 radio @");  Serial.print((int)RF69_FREQ);  Serial.println(" MHz");
}



void loop() {
  delay(1000);  // Wait 1 second between transmits, could also 'sleep' here!

  char radiopacket[20] = "Hello World #";
  itoa(packetnum++, radiopacket+13, 10);
  Serial.print("Sending "); Serial.println(radiopacket);
 
  // Send a message!
  rf69.send((uint8_t *)radiopacket, strlen(radiopacket));
  rf69.waitPacketSent();

  // Now wait for a reply
  uint8_t buf[RH_RF69_MAX_MESSAGE_LEN];
  uint8_t len = sizeof(buf);

  if (rf69.waitAvailableTimeout(500))  {
    // Should be a reply message for us now  
    if (rf69.recv(buf, &len)) {
      Serial.print("Got a reply: ");
      Serial.println((char*)buf);
      Blink(LED, 50, 3); //blink LED 3 times, 50ms between blinks
    } else {
      Serial.println("Receive failed");
    }
  } else {
    Serial.println("No reply, is another RFM69 listening?");
  }
}

void Blink(byte PIN, byte DELAY_MS, byte loops) {
  for (byte i=0; i<loops; i++)  {
    digitalWrite(PIN,HIGH);
    delay(DELAY_MS);
    digitalWrite(PIN,LOW);
    delay(DELAY_MS);
  }
}