Repeater mode

• Introduction
• Repeaters
• How to use
• Example

Introduction

The SWAP stack provides a way to repeat packets along the wireless network. This mechanism relies on special nodes called repeaters, which can also work as standard sensors and actuators. Note that this mode only works with the SWAP protocol.

Repeaters

Repeater nodes need to be powered from an external power source, not a low-power battery since they need to continuously stay in reception mode. Thus, output boards, energy meters and light controls are perfect candidates for acting as repeaters.

In order to avoid unnecessary repeating loops, repeaters maintain transaction tables where any incoming packet is checked before allowing the repetition or not. Each transaction is basically identified by its transmission source, cyclic nonce, SWAP function and register address. Time stamps are also kept associated to each transaction in order to make it expire after a predefined amount of time.

How to use

Repeater mode can be enabled simply by including the following sentence in setup() after swap.init().

// Enable repeater mode
swap.enableRepeater(4);

Where 4 is the amount of times that a packet can be repeated (maximum hop count). You can replace this value by any other value between 1 and 15.

Example

This is a very basic example of a SWAP repeater. Note that repeater has to be initialized after initializing the swap object:

#include "regtable.h"
#include "panstamp.h"

void setup()
{
  // Init panStamp
  //panstamp.init(CFREQ_868);  // Not necessary unless you want a different frequency

  // Init SWAP registers and stack
  swap.init();
  
  // Enable repeater mode
  swap.enableRepeater(4);
}

void loop()
{
}