Introduction

This package provides utilities and Python modules for managing VESNA-based wireless sensor networks that are using the ALH protocol.

In a typical setup, VESNA nodes participate in a ZigBee-based wireless mesh network. On this mesh network each sensor node exposes a HTTP-like interface, supporting two types of requests: GET for state-less information retrieval and POST for state-changing actions.

The ZigBee mesh is established by the coordinator. In addition to a ZigBee interface, the coordinator also typically has an Ethernet adapter. At boot it establishes a TCP/IP SSL tunnel and exposes an ALH service over it.

Usually, the SSL tunnel terminates in an infrastructure server that performs the translation between ALH and a proper HTTP REST interface exposed on the web:

+------+
| node | ALH -  ZigBee mesh
+------+      \
              |                    SSL tunnel
+------+      |      +-------------+         +----------------+
| node | ALH -+- ALH | coordinator | ALH --- | infrastructure | HTTPS -->
+------+      |      +-------------+         +----------------+
              |
+------+      /
| node | ALH -
+------+

Alternatively, coordinator can also be directly connected to a client over a serial line. This setup is typically used for development or debugging:

+------+
| node | ALH -  ZigBee mesh
+------+      \
              |                      serial line
+------+      |      +-------------+
| node | ALH -+- ALH | coordinator | ALH ------------------------------->
+------+      |      +-------------+
              |
+------+      /
| node | ALH -
+------+

These tools transparently support both modes of operation. Typically either URL of the HTTP REST endpoint is given or a character device for the serial line.

Installation

To install system-wide from the package index, run:

$ pip install vesna-alhtools

This should also automatically install the required Python bindings for VESNA spectrum sensor application. More information about it is at: https://github.com/avian2/vesna-spectrum-sensor

To install system-wide from source, run:

$ pip install .

To run tests:

$ tox

Usage

After installation, the following tools are available:

alh-reprogram

Perform over-the-air reprogramming of the coordinator or sensor nodes.

alh-map

Enumerate all the nodes participating in the sensor network by crawling the ZigBee mesh.

Can be used for visualizing the network using Graphviz or network monitoring (via integration into Munin).

alh-tx-test

Signal generator test.

alh-endpoint-server

Simple ALH-to-HTTP endpoint server, useful for testing. It can be used instead of the proper infrastructure server.

Run each with --help as the only argument to get a list of available options.

Note: if the API end-point is using basic authentication, you will be prompted for credentials on the command line.

You can also save credentials into either a file named .alhrc in your home directory or alhrc in the current directory. Format of the file is as in the following example:

Host example.com
User <username>
Password <password>
# more Host, User, Password lines can follow

Several Python modules are installed as well. Refer to demo programs in the demos/ directory for examples on how to use them. Classes and methods are documented with docstring documentation. Some of it is accessible on-line at https://vesna-alh-tools.readthedocs.io/en/latest/

Remote testing with rftest.py

This library provides a DeviceUnderTest class that is compatible with the RF test utility from vesna-spectrum-sensor repository. It allows for testing of radio hardware (e.g. SNE-ISMTV) using the production firmware (e.g. NodeSpectrumSensor application) on a fully assembled node with minimal additional wiring.

Testing setup looks like this:

+----------+ coax +------+ zigbit +-------------+  SSL  +----------------+
| R&S SMBV |----->| node |<-------| coordinator |<------| infrastructure |
+----------+      +------+  ALH   +-------------+       +----------------+
      ^                                                           ^
      | usbtmc    +--------+  HTTPS                               |
      +-----------| rftest |--------------------------------------+
                  +--------+

Run rftest like this:

$ vesna-rftest -i foo -R vesna.alh.rftest.RemoteDeviceUnderTest -O,-Uhttps://...,-u...,-n1

License

Copyright (C) 2018 SensorLab, Jozef Stefan Institute http://sensorlab.ijs.si

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/>.

Authors: Tomaz Solc, <[email protected]>