Development v12

Warning - Product Update

All the resources present on this section belong to Waspmote v12, Waspmote Plug & Sense! v12 and Meshlium v3.8.

If you have a Waspmote v15, Waspmote Plug & Sense! v15 or Meshlium v4.0 please go to the new Development Section.

Check what is your version and what are the differences between the old and the new one in this document.

» SX 08a: TX encrypted

This example shows how to encrypt a plain text message and then send the ciphertext via SX1272 module. Steps performed: - Configurate the LoRa mode - Encrypt the text message - Send a packet with the encrypted message

Required Materials

1 x Waspmote PRO
1 x Battery
1 x MiniUSB wire
1 x SX1272 module (LoRa)
1 x Receiver module with SX_08b example

Notes

- 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.
- This example can be executed in Waspmote v12 and Waspmote v15

Code

/*  
 *  ------ [SX_08a] - TX LoRa encrypted message -------- 
 *  
 *  Explanation: This example shows how to encrypt a plain text message 
 *  and then send the ciphertext via SX1272 module. Steps performed:
 *    - Configurate the LoRa mode
 *    - Encrypt the text message
 *    - Send a packet with the encrypted message   
 *  
 *  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>
#include <WaspAES.h>

// define the destination address to send packets
uint8_t rx_address = 8;

// Define private a 16-Byte key to encrypt message  
char password[] = "libeliumlibelium"; 

// original message on which the algorithm will be applied 
char message[] = "Hello, this is a test";

// define status variable
int e;

// Declaration of variable encrypted message 
uint8_t encrypted_message[300]; 

// Variable for encrypted message's length
uint16_t encrypted_length;


void setup()
{
  // Init USB port
  USB.ON();
  USB.println(F("SX_08a example"));
  USB.println(F("Semtech SX1272 module TX in LoRa, encryption example"));

  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_16_868);
  USB.print(F("Setting Channel CH_16_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 LoRa mode: from 1 to 10
  e = sx1272.setMode(1);  
  USB.print(F("Setting Mode '1'.\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("Sending:")); 
  USB.println(F("----------------------------------------"));
}


void loop()
{

  ////////////////////////////////////////////////////////////////
  // 1. Encrypt message
  ////////////////////////////////////////////////////////////////
  USB.print(F("Original message:"));
  USB.println(message);

  // 1.1. Calculate length in Bytes of the encrypted message 
  encrypted_length = AES.sizeOfBlocks(message);

  // 1.2. Calculate encrypted message with ECB cipher mode and PKCS5 padding. 
  AES.encrypt(  AES_128
    , password
    , message
    , encrypted_message
    , ECB
    , PKCS5); 

  // 1.3. Printing encrypted message    
  USB.print(F("Encrypted message:")); 
  AES.printMessage( encrypted_message, encrypted_length); 

  // 1.4. Printing encrypted message's length 
  USB.print(F("Encrypted length:")); 
  USB.println( (int)encrypted_length);




  ////////////////////////////////////////////////////////////////
  // 2. Send encrypted message to another Waspmote
  ////////////////////////////////////////////////////////////////

  // 2.1. Sending packet before ending a timeout and waiting for an ACK response  
  e = sx1272.sendPacketTimeoutACK(rx_address, encrypted_message, encrypted_length);
  
  // 2.2. Check sending status
  if( e == 0 ) 
  {
    USB.println(F("--> Packet sent OK"));     
  }
  else 
  {
    USB.println(F("--> Error sending the packet"));  
    USB.print(F("state: "));
    USB.println(e, DEC);
  } 

  USB.println();
  delay(5000);
}

Output

H#
SX_08a example
Semtech SX1272 module TX in LoRa, encryption example
----------------------------------------
Setting configuration:
----------------------------------------
Setting Channel CH_16_868. state 0
Setting Header ON. state 0
Setting Mode '1'. state 0
Setting CRC ON. state 0
Setting Power to 'H'. state 0
Setting Node Address to '2'. state 0

----------------------------------------
Sending:
----------------------------------------
Original message:Hello, this is a test
Encrypted message: "A60F4D31AF2768012B86DDD555B51E251AEF6AE88603091101F71C71A8C01884"
Encrypted length:32
--> Packet sent OK

Original message:Hello, this is a test
Encrypted message: "A60F4D31AF2768012B86DDD555B51E251AEF6AE88603091101F71C71A8C01884"
Encrypted length:32
--> Packet sent OK

Original message:Hello, this is a test
Encrypted message: "A60F4D31AF2768012B86DDD555B51E251AEF6AE88603091101F71C71A8C01884"
Encrypted length:32

...

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