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Communication / LoRa:

» SX 03b: RX ACK

This example shows how to configure the SX1272 module in LoRa mode and then receive packets with plain-text payloads sending an acknowledgement (ACK) to the sender.

Required Materials

1 x Waspmote PRO
1 x Battery
1 x MiniUSB wire
1 x SX1272 module (LoRa)
1 x Sender module with SX_03a example

Notes

* This is part of a two-code example. A sender Waspmote needs to be used with the related 03a example.
* The SX1272 module is provided with a special 4.5 dBi antenna, which enables maximum range. The only exception is Smart Parking; in this case the antenna is smaller, 0 dBi, to fit inside the enclosure.
* It is not recommended to work without an antenna screwed to the module. The module could be damaged due to RF reflections.
* The SX1272 module can only be used in special Waspmote units which have been modified to drive the SPI pins to SOCKET0. (only SOCKET0 is available for SX1272)
* This module does not save the configuration. So, the network settings as the mode or the channel MUST be configured every time it is switched on.

Code

/*
 *  ------ [SX_03b] - RX LoRa with ACKs -------- 
 *
 *  Explanation: This example shows how to configure the semtech 
 *  module in LoRa mode and then receive packets with plain-text payloads
 *  sending an acknowledgement (ACK) to the sender.
 *
 *  Copyright (C) 2014 Libelium Comunicaciones Distribuidas S.L. 
 *  http://www.libelium.com 
 *  
 *  This program is free software: you can redistribute it and/or modify 
 *  it under the terms of the GNU General Public License as published by 
 *  the Free Software Foundation, either version 3 of the License, or 
 *  (at your option) any later version. 
 *  
 *  This program is distributed in the hope that it will be useful, 
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of 
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 *  GNU General Public License for more details. 
 *  
 *  You should have received a copy of the GNU General Public License 
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>. 
 *  
 *  Version:           0.1
 *  Design:            David Gascón 
 *  Implementation:    Covadonga Albiñana, Yuri Carmona
 */

// Include this library to transmit with sx1272
#include <WaspSX1272.h>

// status variable
int8_t e;


void setup() 
{
  // Init USB port
  USB.ON();
  USB.println(F("SX_03b example"));
  USB.println(F("Semtech SX1272 module RX in LoRa with ACKs"));

  USB.println(F("----------------------------------------"));
  USB.println(F("Setting configuration:")); 
  USB.println(F("----------------------------------------"));

  // Init sx1272 module
  sx1272.ON();

  //// Options to configure: ////

  // Select frequency channel
  e = sx1272.setChannel(CH_14_868);  
  USB.print(F("Setting Channel CH_14_868.\t state ")); 
  USB.println(e);

  // Select implicit (off) or explicit (on) header mode
  e = sx1272.setHeaderON();
  USB.print(F("Setting Header ON.\t\t state "));  
  USB.println(e); 

  // Select mode (mode 10 is the faster)
  e = sx1272.setMode(10);
  USB.print(F("Setting Mode '10'.\t\t state ")); 
  USB.println(e);  
  
  // Select CRC on or off
  e = sx1272.setCRC_ON();
  USB.print(F("Setting CRC ON.\t\t\t state "));
  USB.println(e); 

  // Select output power (Max, High or Low)
  e = sx1272.setPower('H');
  USB.print(F("Setting Power to 'H'.\t\t state "));  
  USB.println(e); 

  // Select the node address value: from 2 to 255
  e = sx1272.setNodeAddress(2);
  USB.print(F("Setting Node Address to '2'.\t state "));
  USB.println(e);
  USB.println();

  delay(1000);  

  USB.println(F("----------------------------------------"));
  USB.println(F("Receiving:")); 
  USB.println(F("----------------------------------------"));
}


void loop()
{
  // Receiving packet and sending an ACK response
  e = sx1272.receivePacketTimeoutACK(10000);

  // check rx status
  if( e == 0 )
  {
    USB.println(F("\nShow packet received: "));

    // show packet received
    sx1272.showReceivedPacket();

  }
  else
  {
    USB.print(F("\nReceiving packet TIMEOUT, state "));
    USB.println(e, DEC);  
  }  
}

Output

E#
SX_03b example
Semtech SX1272 module RX in LoRa with ACKs
----------------------------------------
Setting configuration:
----------------------------------------
Setting Channel CH_14_868. state 0
Setting Header ON. state 0
Setting Mode '10'. state 0
Setting CRC ON. state 0
Setting Power to 'H'. state 0
Setting Node Address to '2'. state 0

----------------------------------------
Receiving:
----------------------------------------

Show packet received:
==============================
dest: 2
src: 7
packnum: 0
length: 29
retry: 0
payload (HEX): 746869735F69735F7468655F646174615F6D657373616765
payload (string): this_is_the_data_message
==============================

Show packet received:
==============================
dest: 2
src: 7
packnum: 1
length: 29
retry: 0
payload (HEX): 746869735F69735F7468655F646174615F6D657373616765
payload (string): this_is_the_data_message
==============================
...

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