AP Bridge Integrator's Guide

Introduction

The SmartMesh IP VManager supports networks with multiple Access Point Motes (APMs) to improve ingress/egress bandwidth and provide redundancy. APMs connect to the VManager through a backhaul connection. This document describes the ideal full featured AP Bridge which includes an APM (the DC2274A-B) and a Linux computer that connects to the VManager.  A block diagram of the full featured AP Bridge is shown in figure 1. 
Figure 1 - AP Bridge block diagram
The AP Bridge consists of:
  • An AP Mote (APM)
  • AP Bridge software including an AP Connector (APC) that connects to the APM through a serial connection. 
  • A backhaul interface to connect to the server-based VManager. 
  • An embedded Linux platform - the examples use a Raspberry Pi running Raspbian, but other Linux distributions can be used. 

Optional components include:
  • A pulse-per-second (PPS) input to the AP mote to slave to GPS time
  • A GPS daemon (GPSd) process that speaks the National Marine Electronics Association (NMEA) 0183 protocol to receive date and status information from a GPS receiver
  • A command line interface (CLI) for human interaction with the APM. It can either be a direct connection or tunneled through the backhaul connection.

AP Bridge Software / Connector (APC)

The DC2274A-B uses an FTDI USB-to-serial converter to connect the APM serial API directly to a Linux host.  The AP Bridge software is run on that host.  

A Raspberry Pi reference implementation uses the Pi's Ethernet connection (speed varies by model) as the backhaul. The AP Bridge software runs on the Pi.

It is possible to connect the APM directly to the VManager and run the APC on the VM. This is described in the SmartMesh IP User's Guide in the section on VManager installation.

Next Steps

The remainder of this document presents an overview of the AP Bridge software, describes how to build the AP Bridge software on custom hardware, and how to integrate the AP Bridge into a Linux distribution.